Antenna channel sounding method and apparatus, and storage medium

Abstract

Provided are an antenna channel sounding method and apparatus, and a storage medium, to implement antenna selection in a large-scale antenna scenario.SOLUTION: In this application, the first communications apparatus sends the first frame and the first PPDU to the second communications apparatus. The first frame includes first indication information for indicating the second communications apparatus to perform transmit antenna channel sounding. The first PPDU is an NDP. The first PPDU includes a first identifier field indicating an identifier of the first transmit antenna set. In this way, the second communications apparatus may determine the correspondence between the transmit antenna channel sounding result corresponding to the received PPDU and the identifier of the transmit antenna set, and may determine the identifier of the selected transmit antenna set based on the one or more transmit antenna channel sounding results.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present application relates to the field of communications, and in particular to an antenna channel sounding method, apparatus, and storage medium. [Background technology]

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Chinese Patent Application No. 202111295867.0, filed with the State Intellectual Property Office of China on November 3, 2021, entitled "ANTENNA CHANNEL SOUNDING METHOD, APPARATUS, AND STORAGE MEDIUM," the entire contents of which are incorporated herein by reference.

[0003] Wireless local area networks (WLANs) have evolved from 802.11a / b / g, 802.11n, and 802.11ac to 802.11ax. 802.11a / b / g support only a single spatial stream and do not support multiple-input multiple-output (MIMO). 802.11n supports MIMO with up to four space-time streams. 802.11ac and 802.11ax support up to eight space-time streams. 802.11be, the next generation standard for 802.11ax, has been described, further increasing the maximum number of space-time streams to 16. For space-time streams (STSs), both distinct spatial streams (SSs) in the time dimension and space-time block coding (STBC) are considered. When STBC is not used at the transmitting end, the space-time stream may also be referred to as a spatial stream. The 802.11be standard specifies that STBC is not used, and therefore the space-time stream may be uniformly referred to as a spatial stream.

[0004] To support multiple spatial streams, a device needs to include multiple radio frequency chains (RF chains). In some implementations, the device may be equipped with more antennas (or, more precisely, antenna elements) than radio frequency chains and select an antenna set (or antenna pattern) according to an antenna selection procedure to perform data transmission, thereby further improving transmission performance. For example, selecting an antenna pattern may reduce the amount of conditions for an equivalent channel at the transmitting end and the receiving end, improve the equivalent channel, increase the transmitted spatial streams, and improve system throughput.

[0005] In some antenna selection procedures, a device may perform antenna set selection based on antenna channel sounding results corresponding to different antenna sets (or antenna patterns). However, introducing more spatial streams means introducing more antennas, and conventional techniques are only applicable to the 802.11n standard and support antenna selection procedures with only up to four radio frequency chains, eight antennas, and 16 antenna sets. Furthermore, the 802.11be standard requires the introduction of 16 spatial streams and supports up to 16 radio frequency chains. Furthermore, MIMO technology introduces more antennas. Therefore, how to make the antenna selection procedure applicable to large-scale antennas becomes an urgent problem that needs to be solved. Summary of the Invention

[0006] The embodiments of the present application provide an antenna channel sounding method, an apparatus, and a storage medium for performing antenna channel sounding, which are applicable to antenna channel sounding in a large-scale antenna scenario, and thus antenna selection can be performed based on the antenna channel sounding result in the large-scale antenna scenario.

[0007] According to a first aspect, an embodiment of the present application provides an antenna channel sounding method. In the method, a first communication device sends a first frame to a second communication device. The first frame includes first indication information. The first indication information indicates to the second communication device to perform transmit antenna channel sounding. The first communication device sends a first physical layer protocol data unit (PPDU) to the second communication device. The first PPDU is used by the second communication device to perform transmit antenna channel sounding. The first PPDU includes a first identifier field. The first identifier field indicates an identifier of a first transmit antenna set.

[0008] The first PPDU may include a data field, or the first PPDU may not include a data field. For example, the first PPDU may be an NDP that does not include a data field. Because the NDP does not include a data field, overhead may be reduced.

[0009] Furthermore, in the present application, since the NDP includes a first identifier field indicating an identifier of a first transmit antenna set, the second communication device can determine a correspondence between the transmit antenna channel sounding result corresponding to the NDP and the identifier of the transmit antenna set, and the second communication device can determine the identifier of the transmit antenna set to be selected based on one or more transmit antenna channel sounding results, which prevents the second communication device from erroneously matching the selected transmit antenna channel sounding result with the transmit antenna set, and can perform antenna selection based on the antenna channel sounding result in a large-scale antenna scenario.

[0010] In a possible implementation, a first communication device may send one or more PPDUs to a second communication device. The first PPDU is one of the one or more PPDUs. The second communication device may perform transmit antenna channel sounding based on the received one or more PPDUs to obtain transmit antenna channel sounding results. Furthermore, the second communication device may select a transmit antenna set based on the obtained transmit antenna channel sounding results and indicate an identifier of the selected transmit antenna set to the first communication device to perform antenna selection based on the antenna channel sounding results in a large antenna scenario. For example, the first communication device may receive a second frame from the second communication device. The second frame includes a first antenna selection feedback result. The first antenna selection feedback result includes a third identifier field. The third identifier field may be used to convey an identifier of the transmit antenna set selected by the second communication device. For example, if the transmit antenna set selected by the second communication device is the first transmit antenna set, the third identifier field may indicate the identifier of the first transmit antenna set.

[0011] In a possible implementation, before the first communication device sends the first frame to the second communication device, the first communication device receives a third frame including third indication information. The third indication information is used to request the first communication device to send information for performing transmit antenna channel sounding. The third indication information is carried in a high-efficiency variant field of the third frame. Because there are more bits in the high-efficiency variant field used to carry related commands for the antenna selection procedure, the solution provided in the present application can support more PPDUs (e.g., more than 16 PPDUs) and more antenna sets (e.g., more than 16 antenna sets). Therefore, antenna selection can be implemented based on antenna channel sounding results in a large-scale antenna scenario.

[0012] In a possible implementation, the first communication device and the second communication device may conduct negotiation. The second communication device learns the transmit antenna sets supported by the first communication device through the negotiation. After the negotiation, the first communication device and the second communication device configure a group identifier for the transmit antenna set supported by the first communication device. For example, before the first communication device sends a first frame to the second communication device, the first communication device sends a fourth frame to the second communication device. The fourth frame includes a fourth identifier field. The fourth identifier field indicates an identifier of at least one transmit antenna set supported by the first communication device. The identifier of the at least one transmit antenna set includes the identifier of the first transmit antenna set.

[0013] Furthermore, the first communication device may further indicate to the second communication device a transmit antenna set corresponding to an identifier of a transmit antenna set supported by the first communication device. In this way, the first communication device can learn the transmit antenna set identifier of each transmit antenna set, and thus the transmit antenna set identifier is carried when the PPDU is sent. Furthermore, the second communication device can determine the antennas specifically included in the identifier of the first transmit antenna set based on the identifier of the first transmit antenna set indicated by the first identifier field in the received first PPDU. It may be seen that the second communication device may obtain more antenna set-related information through negotiation and subsequently obtain more link-related information, thereby further assisting another subsequent procedure.

[0014] In a possible implementation, before the first communication device sends the first frame to the second communication device, the first communication device sends a ninth frame to the second communication device. The ninth frame includes a seventh indication. The seventh indication indicates a total number of transmit antenna sets supported by the first communication device. In this manner, the second communication device can estimate the overhead and duration of the transmit antenna selection procedure based on the seventh indication, and the second communication device can further determine whether to establish an association relationship with the first communication device based on the total number of transmit antenna sets supported by the first communication device.

[0015] According to a second aspect, an embodiment of the present application provides an antenna channel sounding method. In the method, a second communication device receives a first frame from a first communication device. The first frame includes first indication information. The first indication information indicates to the second communication device to perform transmit antenna channel sounding. The second communication device receives a first physical layer protocol data unit (PPDU) from the first communication device. The first PPDU is used by the second communication device to perform transmit antenna channel sounding. The first PPDU includes a first identifier field. The first identifier field indicates an identifier of a first transmit antenna set.

[0016] The first PPDU may include a data field, or the first PPDU may not include a data field. For example, the first PPDU may be an NDP. Because the NDP does not include a data field, overhead may be reduced.

[0017] Furthermore, in the present application, since the NDP includes a first identifier field indicating an identifier of a first transmit antenna set, the second communication device can determine a correspondence between the transmit antenna channel sounding result corresponding to the NDP and the identifier of the transmit antenna set, and the second communication device can determine the identifier of the transmit antenna set to be selected based on one or more transmit antenna channel sounding results, which prevents the second communication device from erroneously matching the selected transmit antenna channel sounding result with the transmit antenna set, and can perform antenna selection based on the antenna channel sounding result in a large-scale antenna scenario.

[0018] In a possible implementation, a first communication device may send one or more PPDUs to a second communication device. The first PPDU is one of the one or more PPDUs. The second communication device may perform transmit antenna channel sounding based on the received one or more PPDUs to obtain transmit antenna channel sounding results. Furthermore, the second communication device may select a transmit antenna set based on the obtained transmit antenna channel sounding results and indicate an identifier of the selected transmit antenna set to the first communication device to perform antenna selection based on the antenna channel sounding results in a large antenna scenario. For example, the second communication device may send a second frame to the first communication device. The second frame includes a first antenna selection feedback result. The first antenna selection feedback result includes a third identifier field. The third identifier field may be used to convey an identifier of the transmit antenna set selected by the second communication device. For example, if the transmit antenna set selected by the second communication device is the first transmit antenna set, the third identifier field may indicate the identifier of the first transmit antenna set.

[0019] In a possible implementation, before the second communication device receives the first frame, the second communication device sends a third frame including third indication information. The third indication information is used to request the first communication device to send information for performing transmit antenna channel sounding. The third indication information is carried in a high-efficiency variant field of the third frame. Because there are more bits in the high-efficiency variant field and used to carry related commands for the antenna selection procedure, the solution provided in the present application can support more PPDUs (e.g., more than 16 PPDUs) and more antenna sets (e.g., more than 16 antenna sets). Therefore, antenna selection can be implemented based on antenna channel sounding results in a large-scale antenna scenario.

[0020] In a possible implementation, the first communication device and the second communication device may perform negotiation, through which the second communication device learns a transmit antenna set supported by the first communication device, and after the negotiation, the first communication device and the second communication device configure a group identifier for the transmit antenna set supported by the first communication device.

[0021] For example, before the second communication device receives the first frame, the second communication device receives a fourth frame from the first communication device. The fourth frame includes a fourth identifier field. The fourth identifier field indicates an identifier of at least one transmit antenna set supported by the first communication device. The identifier of the at least one transmit antenna set includes the identifier of the first transmit antenna set.

[0022] Furthermore, the second communication device may further receive from the first communication device a transmit antenna set corresponding to the identifier of the transmit antenna set supported by the first communication device. In this way, the first communication device can learn the transmit antenna set identifier of each transmit antenna set, and thus the transmit antenna set identifier is carried when the PPDU is sent. Furthermore, the second communication device can determine the antennas specifically included in the identifier of the first transmit antenna set based on the identifier of the first transmit antenna set indicated by the first identifier field in the received first PPDU. It may be seen that the second communication device may obtain more antenna set-related information through negotiation and subsequently obtain more link-related information, thereby further assisting another subsequent procedure.

[0023] In one possible implementation, before the second communication device receives the first frame, the second communication device receives a ninth frame from the first communication device. The ninth frame includes a seventh indication. The seventh indication indicates a total number of transmit antenna sets supported by the first communication device. In this manner, the second communication device can estimate the overhead and duration of the transmit antenna selection procedure based on the seventh indication, and can further determine whether to establish an association relationship with the first communication device based on the total number of transmit antenna sets supported by the first communication device.

[0024] According to any one of the first or second aspects and possible implementations of the first or second aspects, the present application further provides a possible implementation in which the first identifier field is located in a preamble of the first PPDU, for example, the first identifier field includes some or all of the bits in the universal signal field and / or some or all of the bits in the very high throughput signal field in the preamble.

[0025] When the first PPDU is an NDP, the existing NDP does not carry the first identifier field, and in the present application, a field in the preamble of the existing NDP can be used to carry the content of the first identifier field, and thus the present application can be better adapted to conventional technology, and the identifier of the first transmit antenna set can also be carried in the NDP.

[0026] Furthermore, in existing protocols, there are some reserved bits in these fields, for example, B20 to B24 and B25 of the first symbol in the universal signal field, B2 and B8 of the second symbol, and B14 and B15 in the ultra-high throughput signal field, and in the embodiments of the present application, the first identifier field is added to the NDP by using bits in these fields, and therefore the embodiments of the present application may be better adapted to conventional technologies.

[0027] Furthermore, to maintain consistency with existing standards, when the present application is applicable to a next-generation standard, the first identifier field may include some or all of the bits in the universal signal field and / or some or all of the bits in the next-generation signal field.

[0028] According to any one of the first or second aspects and possible implementations of the first or second aspects, the present application further provides possible implementations in which the PPDU includes a data field and a preamble. The first identifier field may include some or all bits in at least one of the preamble or the data field. For example, information regarding the identifier of the first transmit antenna set is carried in at least one of the universal signal field, the very high throughput signal field, or the aggregation control subfield of the data field. When the first PPDU includes a data field in addition to the universal signal field and the very high throughput signal field, the aggregation control subfield of the data field may also be used as the first identifier field. In this way, more options may be provided for setting the location of the first identifier field. Furthermore, since an existing field may be used to carry the content of the first identifier field, the present application may be more compatible with conventional techniques.

[0029] Furthermore, to be consistent with existing standards, when the present application is applicable to a next-generation standard, the first identifier field may include some or all of the bits in at least one of the universal signal field, the next-generation signal field, or the aggregation control subfield of the data field.

[0030] According to any one of the first aspect or the second aspect and possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation in which the first frame further includes an amount of NDP. In this way, the second communication device can determine the amount of NDP that needs to be received later based on the first frame and check whether the NDP is missing.

[0031] According to any one of the first or second aspects and possible implementations of the first or second aspects, the present application further provides a possible implementation in which the first frame further includes a second identifier field. The second identifier field indicates an identifier of a first transmit antenna set. The second identifier field in the first frame may include identifiers of multiple transmit antenna sets, for example, multiple transmit antenna sets corresponding to multiple consecutive PPDUs subsequently sent in the first frame. In this way, the first identifier field in the first PPDU may carry some bits corresponding to the identifier of the first transmit antenna set to reduce the amount of bits occupied by the first identifier field in the first PPDU. The second communication device may determine all bits corresponding to the identifier of the first transmit antenna set based on the first identifier field and the second identifier field, and all bits of the transmit antenna set selected by the second communication device (e.g., the second communication device selects the first transmit antenna set) may be indicated to the first communication device, and thus the first communication device determines the transmit antenna set selected by the second communication device based on all bits of the transmit antenna set fed back by the second communication device.

[0032] According to any one of the first or second aspects and possible implementations of the first or second aspects, the present application further provides a possible implementation in which the first indication information and / or the amount of NDP is carried in at least one station information field of the first frame and including the second indication information. In another possible implementation, the second identifier field is of the first frame and includes some or all bits in the at least one station information field including the second indication information. The second indication information indicates that the station information field includes antenna selection-related information. In this way, when the second indication information is identified, the second communication device can determine that the station information field carrying the second indication information carries antenna selection-related information and then obtain the antenna selection-related information from the station information field. The second indication information may distinguish the station information field carrying the antenna selection related information from the station information field corresponding to another conventional station, and thus in a solution in which the station information field carries the antenna selection related information, the station information field corresponding to the conventional station is not affected and compatibility with existing standards is achieved.

[0033] According to any one of the first or second aspects and possible implementations of the first or second aspects, the present application further provides a possible implementation in which the second indication information is carried in an association identifier field in the station information field. For example, a value not indicated for a specific station in existing standards may be used as the second indication information. The second indication information includes one of 2008 to 2043 or 2046. In this manner, the second communication device can determine whether the station information field carries antenna selection-related information or station information corresponding to another second communication device based on the association identifier field. It can be seen that this solution may be more compatible with the prior art.

[0034] According to any one of the first or second aspects and possible implementations of the first or second aspects, the present application further provides a possible implementation in which the second frame includes a multiple-input multiple-output control field, and the third identifier field includes some or all of the bits in the multiple-input multiple-output control field. In this way, the third identifier field can be added to the second frame by using bits in an existing multiple-input multiple-output control (MIMO Control) field. This solution does not further increase the length of the second frame and may not be well-suited to conventional techniques.

[0035] According to any one of the first or second aspects and possible implementations of the first or second aspects, the present application further provides a possible implementation in which the third indication information is carried in at least one of the contents of a control identifier field, an antenna selection command field, or an antenna selection data field in an aggregation control subfield. Since the antenna selection command field and the antenna selection data field are obtained through division of existing standards, the antenna selection command field and the antenna selection data field are also obtained by dividing the A-control subfield in the high-efficiency variant field, and therefore the present application can be more compatible with the command form in existing standards. Furthermore, the third indication information is further carried in at least one of the control identifier field, the antenna selection command field, or the antenna selection data field in the A-control subfield. Since the antenna selection command field and the antenna selection data field also exist in conventional technologies, this solution can be compatible with conventional technologies.

[0036] According to any one of the first aspect or the second aspect and possible implementations of the first aspect or the second aspect, the present application further provides possible implementations in which the amount of bits occupied by the antenna selection command field and the antenna selection data field is greater than 7. The amount of bits occupied by the antenna selection data field is greater than 4. The amount of bits occupied by the antenna selection command field and the antenna selection data field is not greater than 26.

[0037] The design of the antenna selection procedure based on the 802.11n high-throughput control (HTC) field supports up to four radio frequency chains, eight antennas, and 16 antenna sets. In the embodiment of the present application, because the amount of bits in the control information field is large, the MPDU shown in Figure 6 can carry more types of antenna selection commands, and the antenna selection data field also has more than four bits. Therefore, more PPDUs (more than 16 PPDUs) and more antenna sets (more than 16 antenna sets) can be supported.

[0038] According to any one of the first or second aspects and possible implementations of the first or second aspects, the present application further provides a possible implementation in which the first transmit antenna set is one of k1 transmit antenna sets of the first communication device, where k1 is a positive integer. The k1 transmit antenna sets correspond one-to-one to the identifiers of the k1 transmit antenna sets. Because the transmit antenna sets correspond one-to-one to the identifiers of the transmit antenna sets, the second communication device receives two PPDUs containing the same antenna set identifier at different times. If the detected channel changes, the second communication device may determine that the antenna set has not changed, and therefore that the channel itself has changed, because the antenna set identifiers included in the two PPDUs are the same.

[0039] According to any one of the first aspect or the second aspect and possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation in which the first identifier field includes all bits corresponding to an identifier of the first transmit antenna set, so that the second communication device can uniquely determine the identifier of the transmit antenna set based on the first identifier field carried in the PPDU.

[0040] According to any one of the first and second aspects and possible implementations of the first and second aspects, the present application further provides a possible implementation in which the first identifier field includes some bits corresponding to an identifier of the first transmit antenna set, thereby reducing the bits used in the preamble of the PPDU.

[0041] According to any one of the first or second aspects and possible implementations of the first or second aspects, the present application further provides a possible implementation in which the third frame sent by the second communication device to the first communication device may further include a quantity of PPDUs. In this way, the first communication device may determine how many PPDUs to send based on the quantity of PPDUs carried in the third frame, and thus the first communication device determines the quantity of PPDUs to be subsequently sent based on the requirements of the second communication device, and the quantity of PPDUs subsequently sent by the first communication device matches the requirements of the second communication device as much as possible.

[0042] According to any one of the first and second aspects and possible implementations of the first and second aspects, the present application further provides a possible implementation in which the first identifier field includes a group identifier of the first transmit antenna set and / or a sequence number of the first PPDU, which can improve the flexibility of the solution.

[0043] According to a third aspect, an embodiment of the present application provides an antenna channel sounding method. In the method, a first communication device sends an eleventh frame to a second communication device. The eleventh frame includes first indication information. The first indication information indicates to the second communication device to perform transmit antenna channel sounding. The first communication device sends a third physical layer protocol data unit (PPDU) to the second communication device. The third PPDU is used by the second communication device to perform transmit antenna channel sounding. The third PPDU includes M1 first information fields corresponding to M1 transmit antenna sets, where M1 is an integer greater than 1. The first information field is used to perform transmit antenna channel sounding. The first information field includes at least one of an EHT short training field, an EHT long training field, and a packet extension field. The first communication device may aggregate PPDUs corresponding to the M1 transmit antenna sets that need to be sent in one PPDU to reduce overhead, improve antenna selection efficiency, and improve system throughput.

[0044] According to a fourth aspect, an embodiment of the present application provides an antenna channel sounding method. In the method, a second communication device receives an eleventh frame from a first communication device. The eleventh frame includes first indication information. The first indication information indicates to the second communication device to perform transmit antenna channel sounding. The second communication device receives a third PPDU from the first communication device. The third PPDU is used by the second communication device to perform transmit antenna channel sounding. The third PPDU includes M1 first information fields corresponding to M1 transmit antenna sets, where M1 is an integer greater than 1. The first information field is used to perform transmit antenna channel sounding. The first information field includes at least one of an EHT short training field, an EHT long training field, and a packet extension field. The first communication device may aggregate PPDUs corresponding to the M1 transmit antenna sets that need to be sent in one PPDU to reduce overhead, improve antenna selection efficiency, and improve system throughput.

[0045] In accordance with any one of the third or fourth aspects and possible implementations of the third or fourth aspects, the present application further provides possible implementations in which the third PPDU includes a preamble. The preamble includes at least one of a legacy short training field, a legacy long training field, a legacy signal field, a repeated legacy signal field, a universal signal field, or an ultra-high throughput signal field. In this way, the portion shared by all transmit antenna sets may be sent only once to reduce overhead.

[0046] According to any one of the third or fourth aspects and possible implementations of the third or fourth aspects, the present application further provides possible implementations in which the durations of the packet extension fields in any two of the M first information fields are the same, thereby improving the consistency of the reception procedure.

[0047] According to any one of the third or fourth aspects and possible implementations of the third or fourth aspects, the present application further provides possible implementations in which the packet extension fields in at least two of the M1 first information fields have different durations. For example, packet extension fields other than the last packet extension field may be shorter than the last packet extension field, sufficient for antenna switching by the first communication device. In this way, signaling transmission efficiency may be improved.

[0048] According to a fifth aspect, an embodiment of the present application provides an antenna channel sounding method. In the method, a first communication device sends a fifth frame to a second communication device. The fifth frame includes fourth indication information. The fourth indication information indicates to the first communication device that receive antenna channel sounding is to be performed. The first communication device receives a second PPDU from the second communication device. The second PPDU is used by the first communication device to perform receive antenna channel sounding. The second PPDU includes a fifth identifier field. The fifth identifier field indicates an identifier of a first receive antenna set.

[0049] The second PPDU may include a data field, or the second PPDU may not include a data field. For example, the second PPDU may be an NDP. Because the NDP does not include a data field, overhead may be reduced.

[0050] Furthermore, the first communication device may perform receive antenna channel sounding on the first receive antenna set based on the second PPDU to obtain receive antenna channel sounding results corresponding to the first receive antenna set. Because the NDP includes a fifth identifier field indicating an identifier of the first receive antenna set, the first communication device may determine a correspondence between the receive antenna channel sounding results corresponding to the NDP and the identifiers of the receive antenna sets, and the first communication device may determine an identifier of the receive antenna set to be selected based on one or more receive antenna channel sounding results. This prevents the first communication device from erroneously matching the selected receive antenna channel sounding results with the receive antenna set, and allows the first communication device to perform antenna selection based on the antenna channel sounding results in a large-scale antenna scenario.

[0051] In a possible implementation, the second communication device may send one or more PPDUs to the first communication device. The second PPDU is one of the one or more PPDUs. The first communication device may perform receive antenna channel sounding based on the received one or more PPDUs to obtain receive antenna channel sounding results. Furthermore, the first communication device may select a receive antenna set based on the obtained receive antenna channel sounding results and indicate an identifier of the selected receive antenna set to the second communication device to perform antenna selection based on the antenna channel sounding results in a large antenna scenario. For example, the first communication device may send a sixth frame to the second communication device. The sixth frame includes a second antenna selection feedback result. The second antenna selection feedback result includes a seventh identifier field. The seventh identifier field may be used to convey an identifier of the receive antenna set selected by the first communication device. For example, if the receive antenna set selected by the first communication device is the first receive antenna set, the seventh identifier field may indicate the identifier of the first receive antenna set.

[0052] In a possible implementation, before the first communication device sends the fifth frame to the second communication device, the method further includes: the first communication device receiving a seventh frame including sixth indication information. The sixth indication information is used to request the first communication device to send information for performing receive antenna channel sounding. The sixth indication information is carried in a high-efficiency variant field of the seventh frame. Because the sixth indication information is in the high-efficiency variant field and has a larger amount of bits used to carry related commands of the antenna selection procedure, the solution provided in the present application can support more PPDUs (e.g., more than 16 PPDUs) and more antenna sets (e.g., more than 16 antenna sets). Therefore, antenna selection can be implemented based on antenna channel sounding results in a large-scale antenna scenario.

[0053] In a possible implementation, the first communication device and the second communication device may perform negotiation, through which the second communication device learns a receive antenna set supported by the first communication device, and after the negotiation, the first communication device and the second communication device configure a group identifier for the receive antenna set supported by the first communication device.

[0054] For example, in a possible implementation, before the first communication device sends the fifth frame to the second communication device, the method further includes: the first communication device sending an eighth frame to the second communication device, the eighth frame including an eighth identifier field, the eighth identifier field indicating an identifier of at least one receive antenna set supported by the first communication device, and the identifier of the at least one receive antenna set including the identifier of the first receive antenna set.

[0055] Furthermore, the first communication device may further indicate to the second communication device a receive antenna set corresponding to an identifier of a receive antenna set supported by the first communication device. In this manner, the second communication device may convey the identifier of the receive antenna set when sending a PPDU. Furthermore, the second communication device may determine the antennas specifically included in the first receive antenna set. It may be understood that the second communication device may obtain more antenna set-related information through negotiation, and subsequently obtain more link-related information, thereby further assisting another subsequent procedure.

[0056] For example, in a possible implementation, before the first communication device sends the fifth frame to the second communication device, the method further includes: the first communication device sends a tenth frame to the second communication device. The tenth frame includes eighth indication information. The eighth indication information indicates a total number of receive antenna sets supported by the first communication device. In this manner, the second communication device can estimate the overhead and duration of the receive antenna selection procedure based on the eighth indication information, and the second communication device can further determine whether to establish an association relationship with the first communication device based on the total number of receive antenna sets supported by the first communication device.

[0057] According to a sixth aspect, an embodiment of the present application provides an antenna channel sounding method. In the method, a second communication device receives a fifth frame from a first communication device. The fifth frame includes fourth indication information. The fourth indication information indicates to the first communication device that receive antenna channel sounding is to be performed. The second communication device sends a second PPDU to the first communication device. The second PPDU is used by the first communication device to perform receive antenna channel sounding. The second PPDU includes a fifth identifier field. The fifth identifier field indicates an identifier of a first receive antenna set.

[0058] The second PPDU may include a data field, or the second PPDU may not include a data field. For example, the second PPDU may be an NDP. Because the NDP does not include a data field, overhead may be reduced.

[0059] Furthermore, in the present application, the NDP includes a fifth identifier field indicating an identifier of the first receive antenna set, so that the first communication device can determine a correspondence between the receive antenna channel sounding results corresponding to the NDP and the identifiers of the receive antenna sets, and the first communication device can determine the identifiers of the receive antenna sets to be selected based on one or more receive antenna channel sounding results, which prevents the first communication device from erroneously matching the selected receive antenna channel sounding results with the receive antenna sets, and can perform antenna selection based on the antenna channel sounding results in a large-scale antenna scenario.

[0060] In a possible implementation, the second communication device may send one or more PPDUs to the first communication device. The second PPDU is one of the one or more PPDUs. The first communication device may perform receive antenna channel sounding based on the received one or more PPDUs to obtain receive antenna channel sounding results. Furthermore, the first communication device may select a receive antenna set based on the obtained receive antenna channel sounding results and indicate an identifier of the selected receive antenna set to the second communication device to perform antenna selection based on the antenna channel sounding results in a large antenna scenario. For example, the second communication device may receive a sixth frame from the first communication device. The sixth frame includes a second antenna selection feedback result. The second antenna selection feedback result includes a seventh identifier field. The seventh identifier field may be used to convey an identifier of the receive antenna set selected by the first communication device. For example, if the receive antenna set selected by the first communication device is the first receive antenna set, the seventh identifier field may indicate the identifier of the first receive antenna set.

[0061] In a possible implementation, before the second communication device receives the fifth frame from the first communication device, the method further includes: the second communication device sending a seventh frame including sixth indication information. The sixth indication information is used to request the first communication device to send information for performing receive antenna channel sounding. The sixth indication information is carried in a high-efficiency variant field of the seventh frame. Because the sixth indication information is in the high-efficiency variant field and has a larger amount of bits used to carry related commands of the antenna selection procedure, the solution provided in the present application can support more PPDUs (e.g., more than 16 PPDUs) and more antenna sets (e.g., more than 16 antenna sets). Therefore, antenna selection can be implemented based on antenna channel sounding results in a large-scale antenna scenario.

[0062] In a possible implementation, the first communication device and the second communication device may perform negotiation, through which the second communication device learns a receive antenna set supported by the first communication device, and after the negotiation, the first communication device and the second communication device configure a group identifier for the receive antenna set supported by the first communication device.

[0063] For example, in one possible implementation, before the second communication device receives the fifth frame from the first communication device, the second communication device receives an eighth frame from the first communication device. The eighth frame includes an eighth identifier field. The eighth identifier field indicates an identifier of at least one receive antenna set supported by the first communication device. The identifier of the at least one receive antenna set includes the identifier of the first receive antenna set.

[0064] Furthermore, the first communication device may further indicate to the second communication device a receive antenna set corresponding to an identifier of a receive antenna set supported by the first communication device. In this manner, the second communication device may convey the identifier of the receive antenna set when sending a PPDU. Furthermore, the second communication device may determine the antennas specifically included in the first receive antenna set. It may be understood that the second communication device may obtain more antenna set-related information through negotiation, and subsequently obtain more link-related information, thereby further assisting another subsequent procedure.

[0065] In a possible implementation, before the first communication device sends a fifth frame to the second communication device, the second communication device receives a tenth frame from the first communication device. The tenth frame includes an eighth indication. The eighth indication indicates a total number of receive antenna sets supported by the first communication device. In this manner, the second communication device can estimate the overhead and duration of the receive antenna selection procedure based on the eighth indication, and the second communication device can further determine whether to establish an association relationship with the first communication device based on the total number of receive antenna sets supported by the first communication device.

[0066] According to any one of the fifth or sixth aspects and possible implementations of the fifth or sixth aspects, the present application further provides a possible implementation in which the fifth identifier field is located in a preamble of the second PPDU. For example, the fifth identifier field is some or all of the bits in a universal signal field and / or some or all of the bits in an ultra-high throughput signal field in the preamble. When the second PPDU is an NDP, the existing NDP does not carry the fifth identifier field. In the present application, a field in the preamble of the existing NDP may be used to carry the content of the fifth identifier field. Thus, the present application may be more compatible with conventional techniques, and the identifier of the first receive antenna set may also be carried in the NDP.

[0067] Furthermore, in existing protocols, there are some reserved bits in these fields, for example, B20 to B24 and B25 of the first symbol in the universal signal field, B2 and B8 of the second symbol, and B14 and B15 in the ultra-high throughput signal field, and in the embodiments of the present application, the first identifier field is added to the NDP by using bits in these fields, and therefore the embodiments of the present application may be better adapted to conventional technologies.

[0068] Furthermore, to maintain consistency with existing standards, when the present application is applicable to a next-generation standard, the fifth identifier field may include some or all of the bits in the universal signal field and / or some or all of the bits in the next-generation signal field.

[0069] According to any one of the fifth or sixth aspects and possible implementations of the fifth or sixth aspects, the present application further provides possible implementations in which the PPDU includes a data field and a preamble. The fifth identifier field includes some or all bits in at least one of the preamble or the data field. For example, information regarding the identifier of the first receive antenna set is carried in at least one of the universal signal field, the very high throughput signal field, or the aggregation control subfield of the data field. When the second PPDU includes a data field in addition to the universal signal field and the very high throughput signal field, the aggregation control subfield of the data field may also be used as the fifth identifier field. In this way, more options may be provided for setting the location of the fifth identifier field. Furthermore, since an existing field may be used to carry the content of the fifth identifier field, the present application may be more compatible with conventional techniques.

[0070] Furthermore, to be consistent with existing standards, when the present application is applicable to a next generation standard, information regarding the identifier of the first receive antenna set is carried in at least one of the universal signal field, the next generation signal field, or the aggregation control subfield of the data field.

[0071] According to any one of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation in which the fifth frame further includes an amount of NDP. In this way, the second communication device can determine the amount of NDP that needs to be received later based on the first frame and check whether the NDP is missing.

[0072] According to any one of the fifth or sixth aspects and possible implementations of the fifth or sixth aspects, the present application further provides a possible implementation in which the fifth frame further includes a sixth identifier field. The sixth identifier field indicates an identifier of a first receive antenna set. The sixth identifier field in the fifth frame may include identifiers of multiple receive antenna sets, for example, multiple receive antenna sets corresponding to multiple consecutive PPDUs subsequently sent in the fifth frame. In this way, the fifth identifier field in the second PPDU may carry some bits corresponding to the identifier of the first receive antenna set to reduce the amount of bits occupied by the fifth identifier field in the second PPDU. The first communication device may determine all bits corresponding to the identifier of the first receive antenna set based on the fifth identifier field and the sixth identifier field, and all bits of the transmit antenna set selected by the second communication device (e.g., the second communication device selects the first transmit antenna set) may be indicated to the first communication device, and thus the first communication device determines the transmit antenna set selected by the second communication device based on all bits of the transmit antenna set fed back by the second communication device.

[0073] According to any one of the fifth or sixth aspects and possible implementations of the fifth or sixth aspects, the present application further provides a possible implementation in which the fourth indication information and / or the amount of NDP is for a fifth frame and is carried in at least one station information field including the fifth indication information. In another possible implementation, the sixth identifier field is for the fifth frame and includes some or all bits in the at least one station information field including the fifth indication information. The fifth indication information indicates that the station information field includes antenna selection-related information. In this way, when the fifth indication information is identified, the second communication device can determine that the station information field carrying the fifth indication information carries antenna selection-related information and then obtain the antenna selection-related information from the station information field. The fifth indication information may distinguish the station information field carrying the antenna selection related information from the station information field corresponding to another conventional station, and thus in a solution in which the station information field carries the antenna selection related information, the station information field corresponding to the conventional station is not affected and compatibility with existing standards is achieved.

[0074] According to any one of the fifth or sixth aspects and possible implementations of the fifth or sixth aspects, the present application further provides a possible implementation in which the fifth indication information is carried in an association identifier field in the station information field. For example, a value not indicated for a specific station in existing standards may be used as the fifth indication information. The fifth indication information includes one of 2008 to 2043 or 2046. In this manner, the second communication device can determine whether the station information field carries antenna selection-related information or station information corresponding to another second communication device based on the association identifier field. It can be seen that this solution may be more compatible with conventional techniques.

[0075] According to any one of the fifth or sixth aspects and possible implementations of the fifth or sixth aspects, the present application further provides possible implementations in which the fourth indication information is carried in a trigger type field of the fifth frame, and / or the amount of NDP and / or the sixth identifier field is carried in some or all bits of at least one of the reserved bits of the common information field, the reserved bits of the user information list field, the trigger-dependent common information, or the trigger-dependent user information. Alternatively, the fifth frame may be a second trigger frame. In this solution, bits in the existing second trigger frame may be used to add antenna selection-related information to the second trigger frame. In this way, this solution may be compatible with conventional techniques.

[0076] According to any one of the fifth or sixth aspects and possible implementations of the fifth or sixth aspects, the present application further provides a possible implementation in which the sixth frame includes a MIMO control field, and the seventh identifier field includes some or all of the bits in the MIMO control field. In this way, the third identifier field can be added to the second frame by using bits in an existing MIMO control field. This solution does not further increase the length of the second frame and may not be well-suited to conventional techniques.

[0077] According to any one of the fifth or sixth aspects and possible implementations of the fifth or sixth aspects, the present application further provides a possible implementation in which the sixth indication information is carried in at least one of the contents of a control identifier field, an antenna selection command field, or an antenna selection data field in the A-control subfield. Since the antenna selection command field and the antenna selection data field are obtained through division of existing standards, the antenna selection command field and the antenna selection data field are also obtained by dividing the A-control subfield in the high-efficiency variant field, and therefore the present application may be more compatible with the command form in existing standards. Furthermore, the sixth indication information is further carried in at least one of the control identifier field, the antenna selection command field, or the antenna selection data field in the A-control subfield. The present application may be compatible with conventional techniques.

[0078] According to any one of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides possible implementations in which the amount of bits occupied by the antenna selection command field and the antenna selection data field is greater than 7. The amount of bits occupied by the antenna selection data field is greater than 4. The amount of bits occupied by the antenna selection command field and the antenna selection data field is not greater than 26.

[0079] The design of the antenna selection procedure based on the 802.11n high-throughput control (HTC) field supports up to four radio frequency chains, eight antennas, and 16 antenna sets. In the embodiment of the present application, because the amount of bits in the control information field is large, the MPDU shown in Figure 6 can carry more types of antenna selection commands, and the antenna selection data field also has more than four bits. Therefore, more PPDUs (more than 16 PPDUs) and more antenna sets (more than 16 antenna sets) can be supported.

[0080] According to any one of the fifth or sixth aspects and possible implementations of the fifth or sixth aspects, the present application further provides a possible implementation in which the first receive antenna set is one of k2 receive antenna sets of the first communication device, where k2 is a positive integer. The k2 receive antenna sets correspond one-to-one with identifiers of the k2 receive antenna sets. Because the receive antenna sets correspond one-to-one with the identifiers of the receive antenna sets, the second communication device receives two PPDUs containing the same antenna set identifier at different times. If the detected channel changes, the second communication device may determine that the antenna set has not changed, and therefore that the channel itself has changed, because the antenna set identifiers included in the two PPDUs are the same.

[0081] According to any one of the fifth or sixth aspects and possible implementations of the fifth or sixth aspects, the present application further provides a possible implementation in which the fifth identifier field includes all bits corresponding to an identifier of the first receive antenna set, in this way the second communication device can uniquely determine the identifier of the receive antenna set based on the first identifier field carried in the PPDU.

[0082] According to any one of the fifth or sixth aspects and possible implementations of the fifth or sixth aspects, the present application further provides a possible implementation in which the fifth identifier field includes some bits corresponding to an identifier of the first transmit antenna set, thereby reducing the bits used in the preamble of the PPDU.

[0083] According to any one of the fifth or sixth aspects and possible implementations of the fifth or sixth aspects, the present application further provides a possible implementation, in which the seventh frame sent by the second communication device to the first communication device further includes a quantity of PPDUs. In this way, the first communication device can determine the quantity of PPDUs that need to be subsequently sent by the second communication device based on the quantity of PPDUs carried in the seventh frame, and thus the quantity of PPDUs that need to be subsequently sent by the second communication device and that is determined by the first communication device matches the requirements of the second communication device as much as possible.

[0084] According to any one of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation in which the fifth identifier field includes a group identifier of the first receive antenna set and / or a sequence number of the second PPDU, which can improve the flexibility of the solution.

[0085] According to a seventh aspect, an embodiment of the present application provides an antenna channel sounding method. In the method, a first communication device sends a twelfth frame to a second communication device. The twelfth frame includes fourth indication information. The fourth indication information indicates to the first communication device that receive antenna channel sounding is to be performed. The first communication device receives a fourth PPDU from the second communication device. The fourth PPDU is used by the second communication device to perform receive antenna channel sounding. PDU includes M2 second information fields corresponding to the M2 receive antenna sets, where M2 is an integer greater than 1. The second information fields are used to perform receive antenna channel sounding. The second information fields include at least one of an EHT short training field, an EHT long training field, and a packet extension field.

[0086] The second communication device may aggregate PPDUs corresponding to the M2 receive antenna sets that need to be sent in one PPDU to reduce overhead, improve antenna selection efficiency, and improve system throughput.

[0087] According to an eighth aspect, an embodiment of the present application provides an antenna channel sounding method. In the method, a second communication device receives a twelfth frame from a first communication device. The twelfth frame includes fourth indication information. The fourth indication information indicates to the first communication device that receive antenna channel sounding is to be performed. The second communication device sends a fourth PPDU to the first communication device. The fourth PPDU is used by the second communication device to perform receive antenna channel sounding. The fourth PPDU includes M2 second information fields corresponding to M2 receive antenna sets, where M2 is an integer greater than 1. The second information field is used to perform receive antenna channel sounding. The second information field includes at least one of an EHT short training field, an EHT long training field, and a packet extension field.

[0088] The second communication device may aggregate PPDUs corresponding to the M2 receive antenna sets that need to be sent in one PPDU to reduce overhead, improve antenna selection efficiency, and improve system throughput.

[0089] According to any one of the seventh or eighth aspects and possible implementations of the seventh or eighth aspects, the present application further provides possible implementations in which the fourth PPDU includes a preamble. The preamble includes at least one of a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), a repeated legacy signal field (RL-SIG), a universal signal field (U-SIG), or an ultra-high throughput signal field (EHT-SIG). In this way, the portion shared by all transmit antenna sets may be sent only once to reduce overhead.

[0090] According to any one of the seventh or eighth aspects and possible implementations of the seventh or eighth aspects, the present application further provides possible implementations in which the durations of the packet extension fields in any two of the M second information fields are the same. In this way, the consistency of the receiving procedure can be improved.

[0091] According to any one of the seventh or eighth aspects and possible implementations of the seventh or eighth aspects, the present application further provides possible implementations in which the packet extension fields in at least two of the M2 second information fields have different durations. For example, packet extension fields other than the last packet extension field may be shorter than the last packet extension field, sufficient for antenna switching by the first communication device. In this way, signaling transmission efficiency may be improved.

[0092] According to a ninth aspect, a communication device is provided, including a communication unit and a processing unit. The communication device may be the first communication device described above or the second communication device described above. The communication device may implement any one of the first to eighth aspects and any implementation of the first to eighth aspects. The communication unit is configured to perform functions related to transmission and reception. Optionally, the communication unit includes a receiving unit and a transmitting unit. In a design, the communication device is a communication chip, and the processing unit may be a processing circuit, one or more processors, or a processor core, and the communication unit may be an interface circuit, an input / output circuit, or a port of the communication chip.

[0093] In another design, the communication unit may be a transmitter and a receiver, or the communication unit may be a transmitter machine and a receiver machine.

[0094] Optionally, the communication device further includes a module that may be configured to perform any one of the first to eighth aspects and any implementation of the first to eighth aspects.

[0095] According to a tenth aspect, a communication device is provided, including a processor and a transceiver. The communication device may be the first communication device described above or the second communication device described above. Optionally, the communication device further includes a memory. The memory is configured to store a computer program or instruction. The processor is configured to retrieve the computer program or instruction from the memory and execute the computer program or instruction. When the processor executes the computer program or instruction in the memory, the communication device is capable of performing any one of the first to eighth aspects and any implementation of the first to eighth aspects.

[0096] Optionally, there are one or more processors and one or more memories.

[0097] Optionally, the memory may be integrated into the processor, or the memory and processor may be separately located.

[0098] Optionally, the transceiver may include a transmitter mechanism (transmitter) and a receiver mechanism (receiver).

[0099] According to an eleventh aspect, a communication device is provided, including a processor. The communication device may be the first communication device described above, or the second communication device described above. The processor may be coupled to a memory and configured to perform any one of the first to eighth aspects and any implementation of the first to eighth aspects. The communication device may be the first communication device described above, or the second communication device described above. Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface, and the processor is coupled to the communication interface.

[0100] In one implementation, when the communication device is a first communication device, the communication interface may be a transceiver or an input / output interface. Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0101] In another implementation, when the communication device is a chip or chip system of the first communication device, the communication interface may be an input / output interface, interface circuit, output circuit, input circuit, pin, associated circuitry, etc. on the chip or chip system. The processor may alternatively be implemented as a processing circuit or a logic circuit.

[0102] In one implementation, when the communication device is a second communication device, the communication interface may be a transceiver or an input / output interface. Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0103] In another implementation, when the communication device is a chip or chip system of a second communication device, the communication interface may be an input / output interface, interface circuitry, output circuitry, input circuitry, pins, associated circuitry, etc. on the chip or chip system. The processor may alternatively be implemented as a processing circuit or a logic circuit.

[0104] According to a twelfth aspect, there is provided a system, the system including the first communication device as described above and the second communication device as described above.

[0105] According to a thirteenth aspect, there is provided a computer program product, the computer program product including a computer program (which may also be referred to as code or instructions) that, when executed, enables a computer to perform any one of the first to eighth aspects and any implementation of the first to eighth aspects.

[0106] According to a fourteenth aspect, there is provided a computer-readable storage medium storing a computer program (sometimes referred to as code or instructions) which, when executed on a computer, enables the computer to perform any one of the first to eighth aspects and any implementation of the first to eighth aspects.

[0107] According to a fifteenth aspect, a chip system is provided. The chip system may include a processing circuit. The processing circuit may be configured to perform any one of the first to eighth aspects and any implementation of the first to eighth aspects by using an interface circuit. Optionally, the chip system further includes a memory. The memory is configured to store a computer program (sometimes referred to as code or instructions). The processing circuit may be configured to call and execute the computer program from the memory, such that a device in which the chip system is installed performs any one of the first to eighth aspects and any implementation of the first to eighth aspects.

[0108] According to a sixteenth aspect, a processing device is provided, the processing device including an interface circuit and a processing circuit. The interface circuit may include an input circuit and an output circuit. The processing circuit is configured to receive a signal by using the input circuit and to transmit a signal by using the output circuit, thus implementing any one of the first to eighth aspects and any implementation of the first to eighth aspects.

[0109] In a particular implementation, the processing device may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a trigger, any logic circuit, etc. An input signal received by an input circuit may be, for example, but not limited to, received and input by a receiver, a signal output by an output circuit may be, for example, but not limited to, output to a transmitter and transmitted by the transmitter, and the input circuit and the output circuit may be the same circuit, where the circuit is used as an input circuit and an output circuit at different moments. The particular implementation of the processor and various circuits is not limited by this application.

[0110] In another implementation, the communication device may be some components in the first communication device, for example, an integrated circuit product such as a system chip or a communication chip. The interface circuit may be an input / output interface, interface circuit, output circuit, input circuit, pin, associated circuit, etc. on the chip or chip system. The processing circuit may be a logic circuit on the chip.

[0111] In another implementation, the communication device may be some component in a second communication device, for example, an integrated circuit product such as a system chip or a communication chip. The interface circuit may be an input / output interface, interface circuit, output circuit, input circuit, pin, associated circuit, etc. on a chip or chip system. The processing circuit may be a logic circuit on a chip. [Brief explanation of the drawings]

[0112] [Figure 1] 1 is a schematic diagram of a system architecture to which an embodiment of the present application is applicable; [Figure 2] FIG. 2 is a schematic diagram of another system architecture according to an embodiment of the present application. [Figure 3] 1 is a schematic diagram of the structure of a communication device according to an embodiment of the present application; [Figure 4] 1 is a schematic diagram of the signaling interaction of an antenna channel sounding method according to an embodiment of the present application; [Figure 5] FIG. 2 is a schematic diagram of the signaling interaction of another antenna channel sounding method according to an embodiment of the present application; [Figure 6] FIG. 10 is a schematic diagram of the structure of an MPDU capable of carrying a third frame according to an embodiment of the present application; [Figure 7] FIG. 2 is a schematic diagram of a structure of a first frame when the first frame is an NDPA frame according to an embodiment of the present application; [Figure 8a] 1 is a schematic diagram of the structure of the first PPDU when the first PPDU is an NDP according to an embodiment of the present application; [Figure 8b] 1 is a schematic diagram of the structure of the first PPDU when the first PPDU is an NG sounding NDP according to an embodiment of the present application; [Figure 8c] FIG. 2 is a schematic diagram of a structure of a first PPDU including a data field according to an embodiment of the present application; [Figure 9] FIG. 10 is a schematic diagram of a structure of a MIMO control field in a second frame when the second frame is a beamforming report frame according to an embodiment of the present application; [Figure 10] FIG. 2 is a schematic diagram of the signaling interaction of another antenna channel sounding method according to an embodiment of the present application; [Figure 11] FIG. 10 is a schematic diagram of a frame structure of a third PPDU according to an embodiment of the present application; [Figure 12] 1 is a schematic diagram of the signaling interaction of an antenna channel sounding method according to an embodiment of the present application; [Figure 13] FIG. 2 is a schematic diagram of the signaling interaction of another antenna channel sounding method according to an embodiment of the present application; [Figure 14A] FIG. 10 is a schematic diagram of a structure of a second trigger frame according to an embodiment of the present application; [Figure 14B] FIG. 10 is a schematic diagram of a structure of a second trigger frame according to an embodiment of the present application; [Figure 15] FIG. 10 is a schematic diagram of the structure of a fifth frame when the fifth frame is an NDPA frame according to an embodiment of the present application; [Figure 16a] 1 is a schematic diagram of the structure of a second PPDU when the second PPDU is an NDP according to an embodiment of the present application; [Figure 16b] 1 is a schematic diagram of the structure of a second PPDU when the second PPDU is an NDP according to an embodiment of the present application; [Figure 16c] FIG. 2 is a schematic diagram of a structure of a second PPDU including a data field according to an embodiment of the present application; [Figure 17]FIG. 2 is a schematic diagram of the signaling interaction of another antenna channel sounding method according to an embodiment of the present application; [Figure 18] FIG. 10 is a schematic diagram of a frame structure of a fourth PPDU according to an embodiment of the present application; [Figure 19] FIG. 10 is a schematic diagram of a frame structure of another fourth PPDU according to an embodiment of the present application; [Figure 20] 2 is a schematic diagram of the architecture of another communication device according to an embodiment of the present application; [Figure 21] 2 is a schematic diagram of the architecture of another communication device according to an embodiment of the present application; [Figure 22] 2 is a schematic diagram of the architecture of another communication device according to an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0113] The technical solutions of the present application are described below with reference to the accompanying drawings.

[0114] 1 is a schematic diagram of an example of the architecture of a communication system to which an embodiment of the present application is applicable. As shown in FIG. 1, the communication system includes a first communication device 101 and a second communication device 102. This embodiment of the present application provides an antenna selection solution that can be used to perform antenna selection for devices. In this embodiment of the present application, an example in which antenna selection is performed for the first communication device 101 is used for explanation. If antenna selection needs to be performed for the second communication device 102 for the antenna selection procedure of the second communication device 102, please refer to the antenna selection procedure of the first communication device 101. Details will not be described again.

[0115] The first communication device 101 may include a transmit antenna and a receive antenna. This embodiment of the present application provides a solution for selecting a transmit antenna for the first communication device 101. In this solution, the first communication device 101 sends a first frame to the second communication device 102. The first frame includes first indication information. The first indication information indicates to the second communication device to perform transmit antenna channel sounding. The first communication device 101 sends a first physical layer protocol data unit (PPDU) to the second communication device 102. The first PPDU includes a first identifier field. The first identifier field indicates an identifier of the first transmit antenna set.

[0116] In a possible implementation, the first PPDU may be a PPDU that includes a data field.

[0117] In another possible implementation, the first PPDU may not include a data field. For example, the first PPDU is a null data packet (NDP). In this embodiment of the present application, the NDP may also be referred to as a null data packet. The NDP may not include a data field.

[0118] When the first PPDU is an NDP, the overhead can be reduced because the NDP does not include a data field. In particular, in a large-scale antenna scenario, since there is a large number of antenna sets, there is also a large number of PPDUs for transmit antenna channel sounding, and the overhead for transmit antenna selection increases accordingly. However, in this embodiment of the present application, with this solution in which transmit antenna channel sounding is performed based on the NDP, more overhead can be reduced in a large-scale antenna scenario.

[0119] Furthermore, in current possible implementations, because the NDP does not include a data field, the NDP cannot carry PPDU sequence number information. Therefore, the second communication device can only infer the sequence number information of the PPDU corresponding to the NDP based on a series of NDPs received by the second communication device. However, if the second communication device loses the NDP, the second communication device cannot correctly infer the sequence number information of the PPDU corresponding to the received NDP and cannot correctly feed back to the first communication device the correspondence between the transmit antenna channel sounding results and the PPDU sequence number information. Therefore, a transmit antenna selection failure on the first communication device may occur. However, in a large-scale antenna scenario, there are more antenna sets, so there is a higher probability of error when the second communication device determines the sequence number information of the PPDU corresponding to the NDP.

[0120] In the above case, in this embodiment of the present application, a first identifier field indicating the identifier of the first transmit antenna set is added to the NDP. Thus, the second communication device can determine the identifier of the first transmit antenna set corresponding to the received NDP, and determine the transmit antenna channel sounding result obtained based on the NDP as the transmit antenna channel sounding result corresponding to the identifier of the first transmit antenna set. The second communication device can determine a correspondence between the transmit antenna channel sounding result corresponding to the NDP and the identifier of the transmit antenna set, and the second communication device can determine the identifier of the transmit antenna set to be selected based on one or more transmit antenna channel sounding results. This prevents the second communication device from mistakenly matching the selected transmit antenna channel sounding result with the transmit antenna set, and can perform antenna selection based on the antenna channel sounding result in a large-scale antenna scenario. Furthermore, the second communication device and the first communication device can advantageously perform antenna selection error recovery (for example, even if the second communication device makes an error in the sequence number information of the PPDU, the identifier of the transmitting antenna set corresponding to the PPDU can still be correctly determined based on the information indicating the identifier of the transmitting antenna set in the PPDU).

[0121] The above describes an example of an antenna selection procedure for a transmitting antenna in a first communication device. This embodiment of the present application may further provide a solution for selecting a receiving antenna for the first communication device. The following will describe the two solutions in detail separately. The details will not be described here.

[0122] The technical solutions in the embodiments of the present application are applicable to wireless local area network (WLAN) communication systems, global systems for mobile communications, for mobile communication s ,GSM )、It may be applied to various communication systems such as code division multiple access (CDMA) systems, wideband code division multiple access (WCDMA) systems, general packet radio service (GPRS), long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD), universal mobile telecommunications system (UMTS), worldwide interoperability for microwave access (WiMAX) communication systems, subsequent 5th generation (5G) systems, or new radio (NR).

[0123] The following describes application scenarios of the embodiments of the present application and methods in the embodiments of the present application by using a WLAN system as an example.

[0124] In particular, embodiments of the present application may be applied to wireless local area networks (WLANs), and may be applied to any protocol of the IEEE 802.11 series of protocols currently used in WLANs, including 802.11be, and may also be applicable to standards later than 802.11be. A WLAN may include one or more basic service sets (BSSs). Network nodes in a basic service set include access points (APs) and stations (STAs).

[0125] 2 is a schematic diagram of an example of the architecture of another system according to an embodiment of the present application. As shown in FIG. 2, the communication system includes one or more APs and may further include one or more STAs. In FIG. 1, two APs (e.g., AP 201 and AP 202 in FIG. 2) and three STAs (e.g., STA 203, STA 204, and STA 205 in FIG. 2) are used as an example. The first communication device 101 in FIG. 1 may be the AP or the STA in FIG. 2. The second communication device 102 in FIG. 2 may be the AP or the STA in FIG. 2.

[0126] The solution provided in the embodiment of the present application is applicable to communication between APs, for example, communication between AP 201 and AP 202 in Fig. 2. In this case, both the first communication device 101 and the second communication device 102 in Fig. 1 can be APs. For example, the first communication device 101 is AP 201, and the second communication device 102 is AP 202.

[0127] The solution provided in the embodiment of the present application is further applicable to communication between STAs, for example, communication between STA204 and STA205 in Fig. 2. In this case, both the first communication device 101 and the second communication device 102 in Fig. 1 can be STAs. For example, the first communication device 101 is STA204, and the second communication device 102 is STA205.

[0128] The solution provided in the embodiments of the present application is further applicable to communication between one AP and one or more STAs, and is further applicable to communication between multiple APs and one or more STAs, for example, communication between the AP 201 and the STA 203 in FIG. 2. In this case, the first communication device 101 and the second communication device 102 in FIG. 1 may be an AP and a STA, respectively. For example, the first communication device 101 may be the STA 203, and the second communication device is the AP 201. In another example, the first communication device 101 is the AP 201, and the second communication device 102 is the STA 203.

[0129] An application scenario of the embodiments of the present application and the method in the embodiments of the present application are described below by using an example in which the first communication device 101 is an AP and the second communication device 102 is a STA.

[0130] Furthermore, an STA in embodiments of the present application may also be referred to as a system, a subscriber unit, an access terminal, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, a user device, or user equipment (UE). An STA may be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless local area network (e.g., Wi-Fi) communication capability, a wearable device, a computing device, or another processing device connected to a wireless modem.

[0131] The station may be a wireless communication chip, a wireless sensor, a wireless communication terminal, etc. For example, the station may be a tablet computer supporting Wi-Fi communication functionality, a set-top box supporting Wi-Fi communication functionality, a smart television supporting Wi-Fi communication functionality, a smart wearable device supporting Wi-Fi communication functionality, an in-vehicle communication device supporting Wi-Fi communication functionality, a computer supporting Wi-Fi communication functionality, etc. Optionally, the station may support the 802.11be standard. Alternatively, the station may support multiple wireless local area network (WLAN) standards of the 802.11 family, such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, 802.11a, and the next generation following 802.11be.

[0132] An access point in this application may be an extremely high throughput (EHT) STA, or may be a STA to which a particular generation of a future Wi-Fi standard is applicable.

[0133] An AP in an embodiment of the present application may be configured to communicate with an access terminal (e.g., an STA) via a wireless local area network and transmit data from the access terminal to the network side or from the network side to the access terminal. An AP is also called a wireless access point, a hotspot, etc. An AP is an access point for mobile users to access a wired network and is mainly deployed in homes, buildings, and campuses, or outdoors. An AP is equivalent to a bridge connecting a wired network and a wireless network. The main function of an AP is to connect wireless network clients together and then connect the wireless network to Ethernet. In particular, an AP may be a communication server, a router, a switch, a bridge, a computer with a wireless fidelity (Wi-Fi) chip, a mobile phone, etc. Optionally, an AP may be a device that supports multiple WLAN standards, such as 802.11.

[0134] Wireless communication may be implemented between the AP and each of the STAs according to various standards, for example, by using single-user multiple-input multiple-output (SU-MIMO) technology or multi-user multiple-input multiple-output (MU-MIMO) technology.

[0135] For example, access points and stations may be devices used in the Internet of Vehicles, Internet of Things nodes in the Internet of Things (IoT), sensors, etc., smart cameras, smart remote controls, smart water meters, or smart electricity meters in a smart house, sensors in a smart city, etc.

[0136] The communication device provided in the embodiment of the present application may be a wireless communication device that supports parallel transmission of multiple links, and may be referred to as a multi-link device or a multi-band device, for example. Compared with a device that only supports single-link transmission, the multi-link device has higher transmission efficiency and higher throughput.

[0137] A multilink device includes one or more affiliated stations (STAs). An affiliate station is a logical station that can operate on a single link. An affiliate station can be an access point (AP) or a non-access point station (non-AP STA). For ease of explanation, a multilink device whose affiliate station is an AP may be referred to as a multilink AP, multilink AP device, or AP multilink device, and a multilink device whose affiliate station is a non-AP STA may be referred to as a multilink STA, multilink STA device, or STA multilink device.

[0138] Figure 3 is a schematic diagram of an example of the structure of a communication device according to an embodiment of the present application. The communication device shown in Figure 3 may be a schematic diagram of the internal structure of the first communication device 101 in Figure 1, or may be a schematic diagram of the internal structure of the second communication device 102 in Figure 1, or may be a schematic diagram of the internal structure of the AP in Figure 2 (e.g., AP 201 or AP 202 in Figure 2), or may be a schematic diagram of the internal structure of the STA in Figure 2 (e.g., STA 203, STA 204, or STA 205 in Figure 2). The communication device shown in Figure 3 may include multiple antennas and may be a device with three or more antennas.

[0139] As shown in FIG. 3, the communication device includes a physical layer (PHY) processing circuit, a media access control (MAC) processing circuit, a memory, a controller, a scheduler, and a processor.

[0140] The physical layer processing circuit may be configured to process physical layer signals. The MAC layer processing circuit may be configured to process MAC layer signals. The memory may be configured to store signaling information, etc. The controller is a component for controlling. The scheduler is a component for scheduling. The processor may be configured to parse signaling information, processing-related data, etc.

[0141] It may be understood that the processor in the embodiments of the present application may be a Central Processing Unit (CPU), or may be another general-purpose processor, a Digital Signal Processor (DSP), an Application-Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. A general-purpose processor may be a microprocessor, any conventional processor, etc.

[0142] The method steps in the embodiments of the present application may be implemented in a hardware manner or by a processor executing software instructions. The software instructions may include corresponding software modules. The software modules may be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disk, removable hard disk, CD-ROM, or any other form of storage medium well known in the art. For example, a storage medium may be coupled to the processor, so that the processor can read information from and write information to the storage medium. Of course, the storage medium may be a component of the processor. The processor and the storage medium may be disposed in an ASIC.

[0143] Based on the above content, FIG. 4 is a schematic diagram of an example of signaling interaction of an antenna channel sounding method according to an embodiment of the present application.

[0144] In Figure 4, the interaction between the first communication device and the second communication device is used as an example for presentation. In this embodiment of the present application, the first communication device may also be referred to as an antenna selection transmitter, and the second communication device may also be referred to as an antenna selection responder.

[0145] The first communication device in Figure 4 may be the first communication device in Figure 1, may be the AP or STA in Figure 2, or may be the communication device in Figure 3. The second communication device in Figure 4 may be the second communication device in Figure 1, may be the AP or STA in Figure 2, or may be the communication device in Figure 3. The first communication device and the second communication device in Figure 4 may both be APs, both be STAs, or an AP and a STA, respectively. In Figure 4, an example in which the first communication device is an AP and the second communication device is a STA is used for presentation.

[0146] The solution provided in this embodiment of the present application is applicable to a transmit antenna channel sounding procedure between an AP and a single STA, or to a transmit antenna channel sounding procedure between an AP and multiple STAs. Figure 4 is a schematic diagram of an example in which a transmit antenna channel sounding procedure is implemented between an AP and multiple STAs (for example, STA203, STA204, and STA205 in Figure 4).

[0147] As shown in FIG. 4, the method includes the following steps:

[0148] S401: A first communication device sends a first frame to a second communication device, the first frame including first indication information, and the first indication information indicates the second communication device to perform transmit antenna channel sounding.

[0149] Correspondingly, the second communication device receives the first frame from the first communication device.

[0150] S402: The first communication device sends a first physical layer protocol data unit (PPDU) to the second communication device. The first PPDU is used by the second communication device to perform transmit antenna channel sounding. The first PPDU includes a first identifier field. The first identifier field indicates an identifier of a first transmit antenna set.

[0151] Correspondingly, the second communication device receives the first PPDU from the first communication device.

[0152] In a possible implementation, in S402, the first communication device may send one or more PPDUs after sending the first frame and after a short inter-frame space (SIFS), and adjacent PPDUs may also be spaced apart by SIFS. In the figure, SIFS is used as an example, and other periods, such as 25 microseconds, may be used. This is not limited in this solution of the present invention. The first PPDU is one of the one or more PPDUs sent by the first communication device in S402. The PPDU in this embodiment of the present application may also be referred to as a physical layer data packet, i.e., a physical layer data packet.

[0153] In a possible implementation, the first PPDU in S402 may be a PPDU including a data field.

[0154] In another possible implementation, the first PPDU in S402 may not include a data field. For example, the first PPDU may be a null data packet (NDP) that does not include a data field. The NDP does not include a data field and is a special example of a PPDU, typically used for channel sounding. Because the NDP does not include a data field, using the NDP as the first PPDU can reduce overhead. In particular, in a large-scale antenna scenario, there are a large number of antenna sets, so there are also a large number of first PPDUs for transmit antenna channel sounding, and the overhead for transmit antenna selection increases accordingly. However, in this solution in which transmit antenna channel sounding is performed based on the NDP, more overhead can be reduced in a large-scale antenna scenario.

[0155] In a possible implementation, the first communication device may send one or more PPDUs to the second communication device. The first PPDU is one of the one or more PPDUs. The PPDU in the one or more PPDUs may include a PPDU first identifier field, and the PPDU first identifier field in the one or more PPDUs may indicate an identifier of a transmit antenna set corresponding to the PPDU. For example, the first PPDU is used to perform transmit antenna channel sounding for the first transmit antenna set, so the first identifier field in the first PPDU indicates an identifier of the first transmit antenna set. In another example, the first PPDU in the one or more PPDUs may include a PPDU first identifier field. PD If another PPDU other than U is a PPDU used to perform transmit antenna channel sounding for a second transmit antenna set, the first identifier field in the PPDU indicates the identifier of the second transmit antenna set.

[0156] In this embodiment of the present application, the PPDU sent by the first communication device to the second communication device may also be understood as a sounding PPDU used to perform antenna channel sounding, and the second communication device may perform transmit antenna channel sounding based on the received one or more PPDUs to obtain a transmit antenna channel sounding result.

[0157] Furthermore, the second communication device may select a transmit antenna set based on the obtained transmit antenna channel sounding result, and indicate an identifier of the selected transmit antenna set to the first communication device. For example, S403 is performed after S402.

[0158] S403: The second communication device sends a second frame, the second frame including a first antenna selection feedback result, the first antenna selection feedback result including a third identifier field, the third identifier field indicating an identifier of the first transmit antenna set.

[0159] It should be noted that the third identifier field in S403 may carry an identifier of the transmit antenna set selected by the second communication device. For example, if the transmit antenna set selected by the second communication device is the first transmit antenna set, the third identifier field may indicate the identifier of the first transmit antenna set. In this embodiment of the present application, an example in which the transmit antenna set selected by the second communication device is the first transmit antenna set is used for presentation. In actual application, the second communication device may also select another transmit antenna set (in this case, the third identifier field needs to indicate another transmit antenna set). This is not limited in this embodiment of the present application.

[0160] In a possible implementation, in S403, the second communication device performs transmit antenna channel sounding based on the first PPDU to obtain a first antenna selection feedback result, and the first antenna selection feedback result is carried in a second frame for sending.

[0161] In response, the first communication device receives a second frame from the second communication device.

[0162] In this embodiment of the present application, the second communication device that performs transmit antenna channel sounding may be a device with Antenna Selection Capability (ASEL). The antenna selection capability transmitting end (e.g., the first communication device) may perform ASEL channel sounding by using NDP sounding PPDUs, i.e., "ASEL transmitter uses NDP sounding PPDUs for the ASEL sounding" in English. Alternatively, the second frame may be ASEL feedback.

[0163] In a possible implementation, after S402, one or more second communication devices may perform transmit antenna channel sounding based on the first PPDU to obtain an antenna selection feedback result. In S403, one second communication device is used as an example for explanation. For distinction, the antenna selection feedback result of the transmit antenna of STA203 (second communication device) in FIG. 4 is referred to as the first antenna selection feedback result.

[0164] It should be noted that the antenna selection feedback results fed back by different second communication devices may be different or the same. This is not limited in this embodiment of the present application. Alternatively, it may be understood that the transmit antenna sets of the first communication device selected by different second communication devices may be different or the same. This is not limited in this embodiment of the present application. For example, in FIG. 4, STA203 (second communication device) selects the first transmit antenna set, and STA204 may select the first transmit antenna set or another transmit antenna set.

[0165] From the above content, it can be learned that in this embodiment of the present application, since the PPDU includes a first identifier field indicating the identifier of the first transmit antenna set, the second communication device can determine a correspondence between the transmit antenna channel sounding result corresponding to the PPDU and the identifier of the transmit antenna set, and the second communication device can determine the identifier of the transmit antenna set to be selected based on one or more transmit antenna channel sounding results, which prevents the second communication device from erroneously matching the selected transmit antenna channel sounding result with the transmit antenna set, and can perform antenna selection based on the antenna channel sounding result in a large-scale antenna scenario.

[0166] Further description will be provided with reference to FIG. 4. In S402, the first communication device may send one or more PPDUs to the second communication device to be used by the second communication device to perform transmit antenna channel sounding. Each PPDU may correspond to an antenna set of a group of transmit antennas. The antenna set of each group of transmit antennas is indicated by an antenna set identifier (in FIG. 4). identifier , ID) corresponds to one antenna set identifier.

[0167] The antenna set identifiers shown in Figure 4 are antenna set IDs that are 0, 1, ... R, where R can be a positive integer. The PPDUs shown in Figure 4 are designated PPDU(i0), PPDU(i1), ... PPDU(i R ) as shown in FIG. 4 , the first communication device sends PPDU(i0) by using a transmit antenna set whose antenna set ID is 0. The second communication device performs transmit antenna channel sounding based on PPDU(i0) to obtain a transmit antenna channel sounding result corresponding to the transmit antenna set whose antenna set ID is 0. Similarly, the first communication device sends PPDU(i1) by using a transmit antenna set whose antenna set ID is 1, ..., the first communication device sends PPDU(i2) by using a transmit antenna set whose antenna set ID is R. R ) The second communication device obtains a transmit antenna channel sounding result corresponding to a transmit antenna set whose antenna set ID is 1, ..., a transmit antenna channel sounding result corresponding to a transmit antenna set whose antenna set ID is R. Furthermore, the second communication device may select a transmit antenna set for the first communication device based on the R transmit antenna channel sounding results, for example, select a first transmit antenna set, and then indicate the selected first transmit antenna set to the first communication device, so that the first communication device sends data to the second communication device by using the first transmit antenna set.

[0168] The configuration of the antenna set identifiers in Figure 4 is just an example. In practical application, the antenna set identifiers corresponding to consecutive PPDUs sent by the first communication device may be randomly configured, for example, non-consecutively configured or not configured in ascending order. For example, the first communication device may send PPDU(i1) by using a transmitting antenna set whose antenna set ID is 1, and PPDU(i2) by using a transmitting antenna set whose antenna set ID is R. R), may successively send PPDU(i0) by using the transmit antenna set with antenna set ID 0, and so on.

[0169] The following describes the relevant contents of the transmit antenna set identifier described in this embodiment of the present application.

[0170] In a possible implementation, the first communication device includes k1 transmit antenna sets. k1 is a positive integer. R in FIG. 4 may be a positive integer not greater than k1. R may be equal to or less than k1. The k1 transmit antenna sets correspond one-to-one to the identifiers of the k1 transmit antenna sets. In other words, one of the k1 transmit antenna sets corresponds to one of the identifiers of the k1 transmit antenna sets, and one of the identifiers of the k1 transmit antenna sets corresponds to one of the k1 transmit antenna sets. The identifiers of the two transmit antenna sets corresponding to any two transmit antenna sets may be different. The identifiers of the two transmit antenna sets corresponding to any two transmit antenna set identifiers may be different. The first transmit antenna set is one of the k1 transmit antenna sets. The following describes an example in which the first transmit antenna set is used.

[0171] There are several implementations of the transmit antenna set identifier, the descriptions of which are given separately as follows:

[0172] Implementation a1

[0173] In a possible implementation, the identifier of the first transmit antenna set may be the sequence number of the first PPDU corresponding to the first transmit antenna set.

[0174] In implementation a1, the first identifier field may indicate the rank of the first PPDU among the R PPDUs sent by the first communication device. It can be understood that when the PPDU sent by the first communication device in S402 is an NDP, the first identifier field may also indicate the rank of the current NDP among the R NDPs sent by the first communication device. In this manner, the second communication device can determine a correspondence between the first PPDU and the antenna selection feedback result of the transmit antennas based on the sequence number corresponding to the first PPDU indicated by the first identifier field. Thus, the second communication device can indicate to the first communication device the sequence number of the PPDU corresponding to the transmit antenna set selected by the second communication device (e.g., the second communication device selects the first transmit antenna set). In this manner, the first communication device correctly determines the transmit antenna set selected by the second communication device based on the sequence number of the PPDU fed back by the second communication device, thereby implementing a solution for selecting antennas based on antenna channel sounding results in a large-antenna scenario.

[0175] Implementation a2

[0176] In another possible implementation, the identifier of the first transmit antenna set may be a group identifier of the first transmit antenna set.

[0177] The first communication device may obtain a correspondence between the transmit antenna set and the group identifier of the transmit antenna set. In this way, when the first communication device sends a PPDU at S402, indication information indicating the identifier of the transmit antenna set corresponding to the PPDU may be carried.

[0178] The second communication device may obtain the correspondence between the transmitting antenna set and the group identifier of the transmitting antenna set, or may not obtain (or learn) the correspondence between the antenna set and the group identifier of the transmitting antenna set. Because the PPDU received by the second communication device carries indication information indicating the identifier of the transmitting antenna set corresponding to the PPDU, regardless of whether the second communication device learns the correspondence between the antenna set and the group identifier of the transmitting antenna set, the second communication device may obtain (or learn) the correspondence between the antenna set and the group identifier of the transmitting antenna set corresponding to the PPDU. set The second communication device may determine a correspondence between the antenna selection feedback result and the transmit antenna set, and thus the second communication device may indicate to the first communication device an identifier of the transmit antenna set corresponding to the transmit antenna set selected by the second communication device (e.g., the second communication device selects the first transmit antenna set). In this way, the first communication device correctly determines the transmit antenna set selected by the second communication device based on the identifier of the transmit antenna set fed back by the second communication device, thereby selecting antennas based on the antenna channel sounding result in a large antenna scenario.

[0179] The antenna set identifier may further include the following possible implementations:

[0180] Implementation a2-1

[0181] The first communication device may inform the second communication device of the total number of transmit antenna sets supported by the first communication device through negotiation. For example, the first communication device may send a ninth frame to the second communication device. The ninth frame includes seventh indication information. The seventh indication information indicates the total number of transmit antenna sets supported by the first communication device. The ninth frame may be an MPDU. In this manner, the second communication device can estimate the overhead and duration of the transmit antenna selection procedure based on the seventh indication information, and the second communication device can further determine whether to establish an association relationship with the first communication device based on the total number of transmit antenna sets supported by the first communication device.

[0182] The first communication device may configure a transmit antenna set group identifier for a transmit antenna set supported by the first communication device, and the second communication device may not obtain (or learn) a correspondence between the antenna set and the transmit antenna set group identifier.

[0183] Since the transmit antenna set and the transmit antenna set identifier correspond one-to-one, the second communication device receives two PPDUs containing the same antenna set identifier at different times. If the detected channel changes, the second communication device can determine that the channel itself has changed because the antenna set identifiers included in the two PPDUs are the same.

[0184] Implementation a2-2

[0185] In this embodiment of the present application, the correspondence between the transmit antenna sets and the group identifiers in the first communication device may be specified in advance (e.g., specified in a standard). The correspondence may be pre-configured in the first communication device or may be sent to the first communication device by another communication device. In this way, the first communication device can learn the transmit antenna set identifiers of each transmit antenna set, and therefore the transmit antenna set identifiers are carried when the PPDU is sent.

[0186] The correspondence may not be preconfigured in the second communication device, may be preconfigured in the second communication device, or may be sent to the second communication device by another communication device. In this way, the second communication device can determine the antenna specifically included in the identifier of the first transmit antenna set based on the identifier of the first transmit antenna set indicated by the first identifier field in the received first PPDU. Furthermore, since the transmit antenna sets correspond one-to-one with the transmit antenna set identifiers, the second communication device receives two PPDUs containing the same antenna set identifier at different times. If the detected channel changes, the second communication device can determine that the channel itself is changing because the antenna set identifiers included in the two PPDUs are the same. Furthermore, the second communication device can further determine the specific transmit antenna set corresponding to the transmit antenna set identifier to obtain more link-related information and thereby provide assistance for another subsequent procedure.

[0187] Implementation a2-3

[0188] The first communication device and the second communication device negotiate to determine a group identifier for the first set of transmit antennas.

[0189] The first communication device and the second communication device may perform negotiation, through which the second communication device learns a transmit antenna set supported by the first communication device, and after the negotiation, the first communication device and the second communication device configure a group identifier for the transmit antenna set supported by the first communication device.

[0190] For example, the first communication device sends a fourth frame to the second communication device. The second communication device receives the fourth frame. The fourth frame may be an MPDU. The fourth frame includes a fourth identifier field. The fourth identifier field indicates an identifier of at least one transmit antenna set supported by the first communication device. The identifier of the at least one transmit antenna set includes an identifier of the first transmit antenna set.

[0191] In this way, the first communication device can learn the transmit antenna set identifier of each transmit antenna set, and therefore the transmit antenna set identifier is carried when the PPDU is sent. Furthermore, the second communication device can determine the antennas specifically included in the identifier of the first transmit antenna set based on the identifier of the first transmit antenna set indicated by the first identifier field in the received first PPDU. It may be seen that the second communication device may obtain more antenna set-related information through negotiation, and subsequently obtain more link-related information, thereby further assisting another subsequent procedure.

[0192] Note that implementation a1 and implementation a2 may be implemented separately or in combination. For example, the identifier of the first transmit antenna set may include the sequence number of the first PPDU corresponding to the first transmit antenna set and the group identifier of the first transmit antenna set. In this way, the first transmit antenna set can be more accurately identified, and the flexibility of the solution may be improved.

[0193] In this embodiment of the present application, the identifier of the first transmitting antenna set may be represented by one or more characters, or may be represented by one or more bits, for example, by one or more bits corresponding to a binary number. The information carried in the first identifier field includes all or some bits corresponding to the identifier of the first transmitting antenna set. The description is given separately as follows:

[0194] Implementation b1

[0195] The first identifier field includes all bits corresponding to the identifier of the first transmit antenna set. In other words, the first identifier field carries all bits corresponding to the identifier of the first transmit antenna set. In this way, the second communication device can uniquely determine the identifier of the transmit antenna set based on the first identifier field carried in the PPDU.

[0196] Implementation b2

[0197] The bits in the preamble of the PPDU are considered useful, and to reduce the bits used in the preamble of the PPDU, the first identifier field includes some bits corresponding to the identifier of the first transmit antenna set. In this way, the amount of bits occupied by the first identifier field in the PPDU can be reduced. However, this implementation may have the following cases:

[0198] When there are a large number of transmit antenna sets, there may be two PPDUs among the multiple PPDUs sent by the first communication device, and the fields indicating the transmit antenna set identifiers in the two PPDUs may carry the same content, since the first identifier field carries only a few bits corresponding to the identifier of the first transmit antenna set.

[0199] In this case, there may be several implementations. For example, the first communication device may transmit all bits of the identifier of the transmit antenna set corresponding to the PPDU in the first frame. In this way, the second communication device may determine all bits of the identifier of the transmit antenna set corresponding to the PPDU based on the rank of the received PPDU and the field indicating the identifier of the transmit antenna set in the PPDU, and thus the second communication device may indicate all bits of the identifier of the first transmit antenna set selected by the first communication device.

[0200] In another example, the second communication device may transmit the selected first transmission to the first communication device. Shin A Antenna set and some bits corresponding to the identifier of the first transmitting antenna set carried in the PPDU, so that the first communication device determines the first transmitting antenna set based on the rank of the sent PPDU and some bits corresponding to the identifier of the first transmitting antenna set.

[0201] Based on the above content, Figure 5 is a schematic diagram of an example of signaling interaction of an antenna channel sounding method according to an embodiment of the present application. In Figure 5, S501 and S502 are added with reference to Figure 4. It should be noted that S501 and S502 are optional steps and are not required. After S502, the first communication device may perform S401 and S402, and the second communication device may perform S403. The following will further describe the frame in this embodiment of the present application with reference to the schematic diagram of signaling interaction shown in Figure 5.

[0202] As shown in FIG. 5, the method includes the following steps:

[0203] S501: A first communication device sends a first trigger frame.

[0204] The first trigger frame may be used to notify the second communication device that receive antenna selection needs to be performed.

[0205] S502: The second communication device sends a third frame, where the third frame includes third indication information, which is used to request transmit antenna channel sounding.

[0206] In response, the first communication device receives the third frame.

[0207] In this embodiment of the present application, the second communication device may send the third frame based on the trigger of the first trigger frame in S501, or may send the third frame by itself. This is not limited in this embodiment of the present application. For distinction, in FIG. 5, the frame of STA203 (second communication device) used to request the first communication device to send information for performing transmit antenna channel sounding is called the third frame. For another frame sent by the second communication device and used to request the first communication device to send information for performing transmit antenna channel sounding, please refer to the related description of the third frame.

[0208] The third frame may be referred to as a transmit antenna selection sounding request. In another possible implementation, the third indication information may also be understood to indicate to the first communication device to send information for performing transmit antenna channel sounding. The information for performing transmit antenna channel sounding may be understood as a continuous sounding PPDU.

[0209] The third frame may further include an amount of PPDUs requested to be sent by the first communication device. In this way, the first communication device may determine the amount of PPDUs to be sent based on the amount of PPDUs carried in the third frame, and thus the first communication device can determine the amount of PPDUs to be subsequently sent based on the requirements of the second communication device, and thus the amount of PPDUs subsequently sent by the first communication device may match the requirements of the second communication device as closely as possible. The amount of PPDUs sent by the first communication device may be the same as or different from the amount of PPDUs requested in the third frame to be sent by the first communication device.

[0210] In a WLAN, an AP and a STA may transmit control signaling, management signaling, or data by using a Media Access Control (MAC) Protocol Data Unit (MPDU) (or MAC frame for short). A third frame may be carried in an MPDU whose MAC frame header carries a High Throughput Control (HTC) field.

[0211] 6 is a schematic diagram of an example of the structure of an MPDU capable of carrying a third frame according to an embodiment of the present application. As shown in FIG. 6, the MPDU may include a frame header, a frame body, and a frame check sequence. The frame header may include frame control, corresponding address information, sequence control information, etc. The frame body may carry data or management and control information transmitted from an upper layer. The frame check sequence (FCS) may be used to check whether the MPDU is transmitted correctly.

[0212] As shown in Figure 6, the MPDU includes a high throughput control (HT control) field. The HT control field is classified into three variants: a high throughput variant, a very high throughput variant, and a high efficiency variant. The variant related to the third frame can be understood as being a high efficiency variant, or the third indication information is carried in the high efficiency variant field of the third frame.

[0213] The high-efficiency variant of the HT Control field is the A-Control subfield in the HE variant HT Control field, or includes an Aggregated Control (A-control) subfield, also known in English as "the format of the A-Control subfield of the HE variant HT Control field."

[0214] The A-control subfield may carry one to N1 pieces of control information by using a structure of one or more control identifier fields and a control information field. N1 may be a positive integer. In the example of FIG. 6, N1 is an integer greater than 2. The control identifier field may indicate the type of control information or determine the length of the corresponding control information. The antenna selection command field and the antenna selection data field may be obtained by dividing the control information field. The third indication information is carried in at least one of the control identifier field, the antenna selection command field, or the antenna selection data field in the A-control subfield.

[0215] In this embodiment of the present application, a control ID value of the control identifier field that is not used in the standard may be used to indicate a transmit antenna selection procedure. For example, the control ID value of the control identifier field may be 9 or one of 11 to 14. In this case, the length of the control information field may be up to 26 bits.

[0216] The amount of bits occupied by the antenna selection command field and the antenna selection data field may be greater than 7. The amount of bits occupied by the antenna selection command field and the antenna selection data field is not greater than 26. The amount of bits occupied by the antenna selection data field may be greater than 4.

[0217] In this embodiment of the present application, the antenna selection command field and the antenna selection data field in FIG. 6 may be set based on actual requirements. Table 1 shows an example of possible antenna selection command fields and antenna selection data fields. The content of the second row in Table 1 is used as an example for explanation. As shown in Table 1, when the antenna selection command field is 0, it indicates that the current frame is used to perform transmit antenna channel sounding, and the antenna selection data field may indicate the amount of remaining untransmitted PPDUs. The content of other rows is merely an example and will not be described herein.

[0218] [Table 1]

[0219] It can be seen that the design of the antenna selection procedure based on the 802.11n high-throughput control (HTC) field supports up to four radio frequency chains, eight antennas, and 16 antenna sets. In the embodiment of the present application, because the amount of bits in the control information field is large, the MPDU shown in FIG. 6 can carry more types of antenna selection commands, and the antenna selection data field also has more than four bits. Therefore, more PPDUs (more than 16 PPDUs) and more antenna sets (more than 16 antenna sets) can be supported. Furthermore, since the antenna selection command field and the antenna selection data field are obtained through division of the existing standard, the antenna selection command field and the antenna selection data field are also obtained by dividing the A-control subfield in the high-efficiency variant field, and therefore the present application can be more compatible with the command format in the existing standard.

[0220] In S401, the first communication device may send a first frame based on the third frame sent by the second communication device, or may send the first frame by itself. This is not limited in this embodiment of the present application. The first frame may be a frame including first indication information that indicates to the second communication device to perform transmit antenna channel sounding. For example, the first frame may be a null data packet announcement (NDPA) frame.

[0221] The first frame includes first indication information. The first frame may further include an amount of NDP and / or a second identifier field. The second identifier field indicates an identifier of the first transmit antenna set. In this way, the second communication device can determine the amount of NDP that needs to be received later based on the first frame and check whether the NDP is missing.

[0222] In a possible implementation, when the NDPA frame includes a second identifier field, the second identifier field may include all bits corresponding to the identifier of the first transmit antenna set. In this way, the first identifier field in a first PPDU subsequently sent by the first communication device may carry some bits corresponding to the identifier of the first transmit antenna set, thus reducing the amount of bits occupied by the first identifier field in the first PPDU, and the second communication device may determine all bits of the identifier of the first transmit antenna set corresponding to the first PPDU based on the second identifier field and the first identifier field.

[0223] 7 is a schematic diagram of an example of the structure of a first frame when the first frame is an NDPA frame according to an embodiment of the present application. The second identifier field and the amount of NDP are not necessarily included in the NDPA frame. In FIG. 7, an example in which the first frame includes the second identifier field, the amount of NDP, and the first indication information is used for presentation.

[0224] As shown in FIG. 7, the NDPA frame may include Frame Control, Duration, receiver address, transmitter address, sounding dialog token, one or more portions of station information (e.g., STA Info 1, STA Info 2, STA Info 3, ..., STA Info N2 in FIG. 7), and may further include a frame check sequence.

[0225] In this embodiment of the present application, a specific association identifier in the station information field may indicate that the information in the station information field is antenna selection-related information. For example, at least one of the first indication information, the amount of NDP, or the second identifier field may be of the first frame and may be carried in at least one station information field including the second indication information. The second indication information indicates that the station information field includes antenna selection-related information. In this way, when the second indication information is identified, the second communication device may determine that the station information field carrying the second indication information carries antenna selection-related information and then obtain the antenna selection-related information from the station information field. The second indication information may distinguish the station information field carrying antenna selection-related information from a station information field corresponding to another conventional station. Therefore, in a solution in which the station information field carries antenna selection-related information, the station information field corresponding to the conventional station is not affected, and compatibility with existing standards is achieved.

[0226] The second indication information may be carried in an association identifier field in the station information field. The second indication information may include one of 2008 to 2043 or 2046. For example, when the association identifier field is one of 2008 to 2043 or 2046, it indicates that antenna selection-related information is transmitted in the station information field. In this manner, the second communication device may determine, based on the association identifier field, whether the station information field carries antenna selection-related information or carries station information corresponding to another second communication device. It may be seen that this solution may better fit the prior art. In FIG. 7, an example in which the station information 1 field and the station information 2 field carry antenna selection-related information is used for presentation.

[0227] The first indication information may also be referred to as an antenna selection type, antenna selection NDPA variant indication information, or NDPA frame variant subtype. The first indication information further indicates that the variant of the NDPA frame is an antenna selection variant. Generally, an NDPA frame indicating to the second communication device to perform antenna selection is followed by multiple (two or more) NDPs, and an NDPA frame indicating to the second communication device to perform channel sounding is followed by one NDP. The amount of NDPs after an NDPA frame affects the time for the second communication device to receive the NDPs and the time for feedback of the second communication device. Therefore, in this embodiment of the present application, the first indication information indicates to the second communication device that the variant of the NDPA frame is an antenna selection variant. Furthermore, information carried in a specific association identifier field (second indication information) may have a similar effect. In other words, after the second communication device identifies a specific association identifier (second indication information), the second communication device may also determine, based on the second indication information, that the variant of the NDPA frame is an antenna selection variant, since the second indication information indicates that the station information field includes antenna selection related information.

[0228] From the 802.11ax standard to the 802.11be standard, the NDPA frame with the HT control field is no longer supported. In this embodiment of the present application, corresponding antenna selection related information is carried in the station information field of the NDPA frame, so that the information required for antenna selection can be indicated. Furthermore, the association identifier in the association identifier field of the station information field is a special association identifier, and the content of the station information field can be read by multiple second communication devices.

[0229] FIG. 7 is a further schematic diagram of information carried in a normal station information field. In FIG. 7, an example in which the station information N2 field carries information about a normal station is used for presentation. N2 may be an integer greater than 1. As shown in FIG. 7, the association identifier field of the station information N2 field carries the association identifier of the station. The station information N2 field may further include partial bandwidth information (Partial BW Info) to indicate the resource used by the STA to feedback channel state information. The resource may be a segment of consecutive resource units (RUs) indicated by the start index of one RU to the end index of another RU. Furthermore, the number of groupings (Ng) indicates that Ng subcarriers are grouped into one group. Channel state information may be fed back together for groups of subcarriers in a unified manner to reduce the amount of bits occupied for feedback. The codebook size subfield indicates the precision of quantization. Different precisions correspond to different overheads.

[0230] In this embodiment of the present application, the first frame may further indicate which of one or more second communication devices will perform transmit antenna channel sounding. For example, an association identifier field of a station information field in the NDPA frame may carry an association identifier of a second communication device that needs to perform transmit antenna channel sounding. When the second communication device determines that its own association identifier matches the association identifier carried in the association identifier field in the NDPA frame, the second communication device may determine that it needs to perform transmit antenna channel sounding.

[0231] The amount of bits in each field in Figure 7 is used as an example, and the specific amount of bits is not limited in the solution of the present invention. The NDPA frame structure used in the current IEEE 802.11ac, IEEE 802.11ax, or IEEE 802.11be standard can also be used for the NDPA frame in this embodiment of the present application. Alternatively, a new NDPA frame can be further redefined, and related information is carried in the newly defined common field.

[0232] In S402, the first PPDU sent by the first communication device may not include a data field, for example, an NDP, or may include a data field. Figures 8a and 8b respectively show schematic diagrams of an example of the structure of the first PPDU when the first PPDU is an NDP. Figure 8c shows a schematic diagram of an example of the structure of the first PPDU including a data field. The following description is given separately with reference to the accompanying drawings.

[0233] The NDP shown in Figure 8a may be a sounding PPDU in the 802.11be standard. The NDP shown in Figure 8a may be an EHT sounding PPDU, also referred to as an EHT sounding NDP or EHT NDP. The EHT sounding NDP is a transmission mode of an EHT MU PPDU and is used for channel sounding to help the first communication device acquire channel state information between the transmitting end and the receiving end to perform beamforming and resource scheduling.

[0234] As shown in Figure 8a, the EHT sounding NDP may include a preamble and a packet extension (PE), and the first identifier field is located in the preamble of the first PPDU.

[0235] The preamble may include a legacy preamble. The legacy preamble may include a legacy short training field (L-STF), a legacy long training field (L-LTF), and a legacy signal field (L-SIG). The legacy preamble is used to ensure coexistence between new devices and legacy devices. The L-SIG may include a length field, which may indirectly indicate the duration after the L-SIG in the PPDU.

[0236] The preamble may further include a repeated legacy signal field (Repeated L-SIG, RL-SIG) to enhance the reliability of the legacy signal field. Furthermore, an auto-detection method may be provided to help the second communication device identify that the data packet is an EHT PPDU by detecting features such as whether the two symbols are the same and the length remainder in the L-SIG by the receiving end.

[0237] The preamble may further include a Universal Signal Field (U-SIG), which may be present in the PPDUs of the 802.11be standard and subsequent generations. The U-SIG may indicate that the PPDU is an EHT PPDU and a subsequent generation PPDU.

[0238] The preamble may further include an extremely high throughput signal field (EHT-SIG) after the U-SIG. Both the U-SIG and EHT-SIG may carry signaling information needed to demodulate the subsequent data field.

[0239] The first identifier field may include some or all of the bits in the U-SIG and / or some or all of the bits in the EHT-SIG. In the EHT sounding NDP, the U-SIG field may include two symbols, and the EHT-SIG field may include one symbol. Currently, B20 to B24 of the first symbol in the U-SIG and B14 and B15 of the EHT-SIG field are disregarded. B25 of the first symbol in the U-SIG field and B2 and B8 of the second symbol in the U-SIG field are validated. Disregard and validate are two types of reserved bits. In this embodiment of the present application, these reserved bits in existing standards can be used as bits in the first identifier field. In this embodiment of the present application, one or more bits in B20 to B24 of the first symbol in the U-SIG, B14 and B15 of the EHT-SIG field, B25 of the first symbol in the U-SIG field, and B2 and B8 of the second symbol in the U-SIG field can be used as bits in the first identifier field. Therefore, the solution can be compatible with conventional technology.

[0240] The EHT sounding NDP may further include an Extremely High Throughput Short Training Field (EHT-STF) and an Extremely High Throughput Long Training Field (EHT-LTF). The EHT-STF and EHT-LTF may be used for automatic gain control and channel estimation, respectively. Packet extension may provide the second communication device with more time to process the data.

[0241] 8a, the EHT sounding NDP is used as an example to describe the first PPDU. This embodiment of the present application may also be applicable to standards after EHT, such as next generation (NG) sounding NDP.

[0242] 8b is a schematic diagram of an example of the structure of the first PPDU when the first PPDU is an NG sounding NDP. As shown in FIG. 8b, the NG sounding NDP may include a preamble and a packet extension (PE). The first identifier field is located in the preamble of the first PPDU.

[0243] The preamble may include a legacy preamble. The legacy preamble may include a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), a repeated legacy signal field (RL-SIG), a universal signal field (U-SIG), and a next generation signal field (NG-SIG). The first identifier field may be some or all of the bits in the U-SIG and / or some or all of the bits in the NG-SIG. In other words, one or more bits in the U-SIG and the NG-SIG are used as the first identifier field.

[0244] The NG sounding NDP may further include a next generation short training field (NG-STF) and a next generation long training field (NG-LTF). The NG-STF and NG-LTF may be used for automatic gain control and channel estimation, respectively. Packet extension may provide the second communication device with more time to process the data.

[0245] Figure 8c is a schematic diagram of an example of a structure in which a first PPDU includes a data field. Figure 8c is presented by using an example in which a data field is added based on Figure 8b. The first PPDU shown in Figure 8c may also be called an MPDU. Compared with Figure 8b, in Figure 8c, a data field is added in the first PPDU. The data field may include an A-control subfield. For the A-control subfield in Figure 8c, please refer to the related description of the A-control subfield in Figure 6.

[0246] The first identifier field may be some or all of the bits in at least one of the U-SIG, NG-SIG, or data fields. For example, the first identifier field may be bits in the control identifier field, antenna selection command field, and antenna selection data field of FIG. 8c.

[0247] For example, the control identifier field may be one of 9 and 11 to 14. The antenna selection command field may define a new identifier to indicate that the antenna selection command field indicates that the current first PPDU is the first PPDU for transmit antenna channel sounding. The antenna selection data field may indicate an identifier of the first PPDU (e.g., may indicate the sequence number of the first PPDU).

[0248] In another possible implementation, the first identifier field may further include some bits in the A-Control subfield, for example, some bits in the A-Control subfield may be marked as the first identifier field to indicate the identifier of the first PPDU.

[0249] FIG. 8c is presented by using an example in which the first PPDU is an advanced PPDU. The first PPDU in this embodiment of the present application may also be an EHT PPDU including a data field. For example, the first PPDU may be an EHT MPDU including a data field. In a specific structure, a data field may be added to the structure shown in FIG. 8a, and the data field may include an A-Control subfield. For the A-Control subfield, please refer to the related description of the A-Control subfield in FIG. 6. When the first PPDU is an EHT MPDU, the first identifier field may be some or all of the bits of at least one of the U-SIG, EHT-SIG, or data field. For related content, please refer to the above description. Details will not be described again.

[0250] The second frame is MIMO controlled Ofu The MIMO control field may include a MIMO control field. The MIMO control field is located in the frame body and may be carried, for example, in the frame body of an Action frame or an Action No ACK frame. Figure 9 is a schematic diagram of an example of the structure of the MIMO control field in the second frame when the second frame is a beamforming report frame. It should be noted that in order to more clearly reflect the frame structure, the frame structure is divided into three rows in Figure 9 for presentation.

[0251] As shown in FIG. 9, the third identifier field may include some or all of the bits in the MIMO control field. The third identifier field includes all bits corresponding to the identifier of the first transmit antenna set. In this way, the first communication device may determine that the transmit antenna set selected by the second communication device is the first transmit antenna set based on the third identifier field in the second frame. Furthermore, the third identifier field may be added to the second frame by using bits in the existing MIMO Control field. This solution does not further increase the length of the second frame and may not be well-suited to conventional techniques.

[0252] In a possible implementation, the third identifier field may include two parts: an antenna set identifier field and a sounding PPDU sequence number field. The antenna set identifier field may carry a group identifier of the first transmit antenna set, and the sounding PPDU sequence number field may carry a sequence number of the first PPDU corresponding to the first transmit antenna set. In Figure 9, an example in which the third identifier field includes the antenna set identifier field and the sounding PPDU sequence number field is used for presentation. Alternatively, the third identifier field may include only one of the antenna set identifier field and the sounding PPDU sequence number field.

[0253] In another possible implementation, the second frame may further include an antenna selection failure feedback field. When the value of the field is set to 1, it indicates that the current antenna selection has failed. When the value of the field is set to 0, it indicates that the current antenna selection has succeeded. The antenna selection failure feedback field may also be carried in the MIMO control field.

[0254] In yet another possible implementation, the second frame may further include at least one of a compressed beamforming report, a multi-user specific beamforming report, and a channel quality status report, For example, the channel quality status report may include at least one of channel state information (CSI) or channel quality information (CQI) corresponding to the PPDU.

[0255] One or more of the compressed beamforming report, the multi-user specific beamforming report, and the channel quality status report may be carried in a field other than the MIMO control field in the second frame. Of course, at least one of the antenna set identifier field and the sounding PPDU sequence number field included in the third identifier field may alternatively be set in another field. For example, the sounding PPDU sequence number field may be located in the A-Control subfield.

[0256] From the above content, it can be learned that in this embodiment of the present application, for example, when the NDPA frame does not support a high-throughput control field, an antenna selection procedure is designed based on NDPA (first frame) + NDP (PPDU) + feedback (second frame). The antenna selection procedure can be consistent with the current channel sounding procedure, and the devices at the receiving end and the transmitting end are slightly modified, and the implementation is simple.

[0257] Furthermore, it should be noted that in this embodiment of the present application, the second communication device may feed back one antenna selection feedback result, or may feed back multiple antenna selection feedback results.

[0258] For example, the second communication device may select a group of transmit antennas based on the entire bandwidth. In this case, the first transmit antenna set selected by the second communication device is selected based on the entire bandwidth. In another example, the second communication device may select a group of transmit antennas based on a sub-bandwidth. In this case, the first transmit antenna set corresponds to one sub-bandwidth, i.e., the first transmit antenna set is selected based on one sub-bandwidth. Of course, the two transmit antenna sets selected by the second communication device based on the two sub-bandwidths may be the same or different. This is not limited in this embodiment of the present application.

[0259] Furthermore, the second communication device may further separately feed back the selected transmit antenna sets based on different amounts of spatial streams, or may separately feed back the selected transmit antenna sets based on at least one of the amount of channel conditions, signal-to-noise ratio, etc. This is not limited in this embodiment of the present application.

[0260] Furthermore, in another possible implementation, when there are multiple second communication devices, the first communication device may send a first trigger frame to trigger the multiple second communication devices to feedback their respective antenna selection feedback results. Furthermore, the amount of bits in Figure 9 is just an example, and N3 is a positive integer.

[0261] Based on the above content, FIG. 10 is a schematic diagram of an example of signaling interaction of an antenna channel sounding method according to an embodiment of the present application.

[0262] 10, the interaction between the first communication device and the second communication device is used as an example for presentation. In this embodiment of the present application, the first communication device may also be referred to as an antenna selection transmitter, and the second communication device may also be referred to as an antenna selection responder.

[0263] The first communication device in Figure 10 may be the first communication device in Figure 1, may be the AP or STA in Figure 2, or may be the communication device in Figure 3. The second communication device in Figure 10 may be the second communication device in Figure 1, may be the AP or STA in Figure 2, or may be the communication device in Figure 3. The first communication device and the second communication device in Figure 10 may both be APs, both be STAs, or an AP and a STA, respectively. In Figure 10, an example in which the first communication device is an AP and the second communication device is a STA is used for presentation.

[0264] The solution provided in this embodiment of the present application is applicable to a transmit antenna channel sounding procedure between an AP and a single STA, or to a transmit antenna channel sounding procedure between an AP and multiple STAs. Figure 10 is a schematic diagram of an example in which a transmit antenna channel sounding procedure is implemented between an AP and multiple STAs (for example, STA203, STA204, and STA205 in Figure 10).

[0265] As shown in FIG. 10, the method includes the following steps:

[0266] S601: A first communication device sends an 11th frame to a second communication device, the 11th frame including first indication information, and the first indication information indicates to the second communication device to perform transmit antenna channel sounding.

[0267] Correspondingly, the second communication device receives the eleventh frame from the first communication device.

[0268] S602: The first communication device sends a third PPDU to the second communication device, where the third PPDU is used by the second communication device to perform transmit antenna channel sounding.

[0269] Correspondingly, the second communication device receives a third PPDU from the first communication device.

[0270] The third PPDU may include M1 first information fields corresponding to the M1 transmit antenna sets, where M1 is an integer greater than 1. The first information fields are used to perform transmit antenna channel sounding.

[0271] S603: The second communication device feeds back the antenna selection feedback result.

[0272] In this embodiment of the present application, it can be learned from the solution that the first communication device can aggregate PPDUs corresponding to the M1 transmit antenna sets that need to be sent in S602 into one PPDU to reduce overhead, improve antenna selection efficiency, and improve system throughput.

[0273] 11 is a schematic diagram of an example of a frame structure of the third PPDU. As shown in FIG. 11, the third PPDU may include M1 first information fields corresponding to M1 transmit antenna sets. M1 may be an integer greater than 1. The first information fields are used to perform transmit antenna channel sounding.

[0274] The first information field includes at least one of an EHT short training field, an EHT long training field, and a packet extension field. Any two first information fields use different transmit antenna sets. For example, the three transmit antenna sets shown in FIG. 11 are the first information field corresponding to the transmit antenna set with antenna set ID 0, the first information field corresponding to the transmit antenna set with antenna set ID 1, ..., the first information field corresponding to the transmit antenna set with antenna set ID M1, respectively.

[0275] As shown in Figure 11, the third PPDU may further include a preamble. The preamble includes at least one of the following fields: L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, or EHT-SIG. For a related description of the preamble, please refer to the related description of Figure 8a. Details will not be described again in this specification.

[0276] From FIG. 11, it can be seen that in S602, M1 PPDUs corresponding to the M1 transmit antenna sets that originally need to be sent are aggregated into one third PPDU, and thus (M1-1) preambles can be reduced.

[0277] 11, each first information field may include one packet extension field, for example, packet extension 0 in the first information field corresponding to antenna set ID=0, packet extension 1 in the first information field corresponding to antenna set ID=1, ..., packet extension M1 in the first information field corresponding to antenna set ID=M1, as shown in FIG. 11. The duration of any two data extensions in the packet extensions (packet extension 0 to packet extension (M1-1)) other than the last packet extension M1 may be the same. The duration of these packet extension fields may be used to provide more processing time to the second communication device. Furthermore, time may be provided for antenna switching by the first communication device. Furthermore, the duration may be set to a shorter value, sufficient for antenna switching by the first communication device.

[0278] In a possible implementation, the durations of the packet extension fields in at least two of the M1 first information fields may be different. For example, the duration of packet extension M1 may be different from the duration of packet extension 1. The duration of packet extension M1 may be set to a slightly longer value. The duration of packet extension 1 may be set to a slightly shorter value, sufficient for antenna switching by the first communication device. Furthermore, in this implementation, the durations of any two data extensions in a packet extension other than the last packet extension M1 (packet extension 0 to packet extension (M1-1)) may be the same or different.

[0279] In another possible implementation, the duration of the packet extension fields in any two of the M1 first information fields is the same. In this way, the consistency of the reception procedure can be improved.

[0280] Compared with the solution in which the first communication device transmits PPDUs corresponding to M1 transmit antennas, the solution shown in FIG. 11 requires only one third PPDU to transmit M1 groups of information used for transmitting antenna channel sounding. In this solution, the preambles (L-STF to EHT-SIG) and short interframe spacing SIFS of (M1-1) groups can be reduced. When any two times from packet extension 0 to packet extension (M1-1) are equal and the duration of packet extension 0 is shorter than the duration of packet extension M1, the time difference between packet extension M1 and packet extension 0 can be further reduced.

[0281] For example, the preamble (L-STF to EHT-SIG) in the third PPDU lasts a total of 36 microseconds, the duration of packet extension M1 is 16 microseconds, and the SIFS lasts 16 microseconds. If the duration of any one of packet extensions 0 to (M1-1) is 4 microseconds, and M1=64, then compared to transmitting a PPDU corresponding to M1 transmit antennas (where the PPDU includes a preamble and one first information field, and the data extension field included in the first information field is 16 microseconds), in this case, 36×(64−1)+16×(64−1)+(16−4)×(64−1)=4032 microseconds can be saved by transmitting the third PPDU.

[0282] It should be noted that FIG. 11 is only one example of a possible PPDU structure for the third PPDU. In this example, the EHT-SIG is transmitted once. In yet another possible implementation, the EHT-SIG may appear in a group. For example, each first information field includes one EHT-SIG. Furthermore, in FIG. 10, an example in which the first communication device transmits one third PPDU is used for presentation. During actual application, in S602, the first communication device may send one or more third PPDUs, and the amount of the first information field included in the third PPDU may be the same or different.

[0283] Furthermore, it should be noted that Figure 10 provides an implementation in which PPDUs sent by the first communication device may be aggregated in this embodiment of the present application. This implementation may be used in combination with the antenna selection solution provided in Figure 4 or Figure 5, or may be implemented independently. The 11th frame in S601 may be an NDPA frame in this embodiment of the present application.

[0284] When this implementation is used in combination, for the relevant content of S601, please refer to the relevant content of S401, and for the relevant content of the eleventh frame, please refer to the relevant description of the first frame. For the relevant content of S603, please refer to the relevant content of S403. For the relevant content of the antenna selection feedback result, please refer to the relevant description of the second frame. When this implementation is used in combination, the amount of NDP described in FIG. 4 or FIG. 5 may be equal to the amount of the first information field described in FIG. 10. When this implementation is used in combination, for the structure of the first PPDU, please refer to the structure of the third PPDU. In other words, the first PPDU may also include first information fields corresponding to multiple transmit antenna sets. For example, the first PPDU may include a first information field corresponding to the first transmit antenna and further include a first information field corresponding to the second transmit antenna. The first PPDU includes one preamble. Furthermore, a U-SIG in the preamble may be disposed in each first information field. A first identifier field may be carried in each first information field.

[0285] Based on the above content, FIG. 12 is a schematic diagram of an example of signaling interaction of a receive antenna channel sounding method according to an embodiment of the present application.

[0286] 12, the interaction between the first communication device and the second communication device is used as an example for presentation. In this embodiment of the present application, the first communication device may also be referred to as an antenna selection transmitter, and the second communication device may also be referred to as an antenna selection responder.

[0287] The first communication device in Figure 12 may be the first communication device in Figure 1, may be the AP or STA in Figure 2, or may be the communication device in Figure 3. The second communication device in Figure 12 may be the second communication device in Figure 1, may be the AP or STA in Figure 2, or may be the communication device in Figure 3. The first communication device and the second communication device in Figure 12 may both be APs, both be STAs, or an AP and a STA, respectively. In Figure 12, an example in which the first communication device is an AP and the second communication device is a STA is used for presentation.

[0288] The solution provided in this embodiment of the present application is applicable to a receive antenna channel sounding procedure between an AP and a single STA, or to a receive antenna channel sounding procedure between an AP and multiple STAs. Figure 12 is a schematic diagram of an example in which a receive antenna channel sounding procedure is performed between an AP and a STA (for example, STA 203 in Figure 12).

[0289] It should be noted that the solution given in Figure 12 is used to select a receive antenna in the first communication device. The solutions given in Figures 4 and 10 are used to select a transmit antenna in the first communication device. The solution in Figure 12 may be used in combination with the solution in Figure 4 or Figure 10, or may be implemented independently. The solution in Figure 4 or Figure 10 may also be implemented independently, or may be used in combination with the solution in Figure 12. When the solutions in Figures 4 and 12 are used in combination, the first communication device may select a transmit antenna according to the solution in Figure 4 and a receive antenna according to the solution in Figure 12. When the solutions in Figures 10 and 12 are used in combination, the first communication device may select a transmit antenna according to the solution in Figure 10 and a receive antenna according to the solution in Figure 12.

[0290] As shown in FIG. 12, the method includes the following steps:

[0291] S701: A first communication device sends a fifth frame to a second communication device, the fifth frame including fourth indication information, the fourth indication information indicating to the second communication device to perform receive antenna channel sounding on the first communication device.

[0292] Correspondingly, the second communication device receives a fifth frame from the first communication device.

[0293] In this embodiment of the present application, the fifth frame may have multiple implementations. For example, the fifth frame may be a second trigger frame, or the fifth frame may be an NDPA frame. Details will be described below and will not be described here.

[0294] S702: The second communication device sends a second PPDU to the first communication device. The second PPDU is used by the second communication device to perform receive antenna channel sounding. The second PPDU includes a fifth identifier field, and the fifth identifier field indicates an identifier of the first receive antenna set.

[0295] Correspondingly, the first communication device receives a second PPDU from the second communication device.

[0296] In a possible implementation, in S702, the second communication device may send one or more PPDUs after the first communication device sends the fifth frame and after a short inter-frame space (SIFS), and adjacent PPDUs may also be spaced apart by a SIFS. The second PPDU is one of the one or more PPDUs sent by the second communication device in S702.

[0297] In a possible implementation, the second PPDU in S702 may be a PPDU including a data field.

[0298] In another possible implementation, the second PPDU in S702 may not include a data field. For example, the second PPDU is an NDP that does not include a data field. Because the NDP does not include a data field, using the NDP as the second PPDU can reduce overhead. In particular, in a large-scale antenna scenario, since there are a large number of antenna sets, there are also a large number of second PPDUs for receive antenna channel sounding, and the overhead for receive antenna selection increases accordingly. However, in this solution in which receive antenna channel sounding is performed based on the NDP, more overhead can be reduced in a large-scale antenna scenario.

[0299] In a possible implementation, the second communication device may send one or more PPDUs to the first communication device. The second PPDU is one of the one or more PPDUs. The PPDU in the one or more PPDUs may include a fifth identifier field, and the fifth identifier field of the PPDU in the one or more PPDUs may indicate an identifier of a receive antenna set corresponding to the PPDU. For example, because the second PPDU is used to perform receive antenna channel sounding for the first receive antenna set, the fifth identifier field in the second PPDU indicates the identifier of the first receive antenna set. In another example, if another PPDU other than the second PPDU in the one or more PPDUs is a PPDU used to perform receive antenna channel sounding for the second receive antenna set, the fifth identifier field in the PPDU indicates the identifier of the second receive antenna set.

[0300] In this embodiment of the present application, the PPDU sent by the second communication device to the first communication device may also be understood as a sounding PPDU used to perform antenna channel sounding. In a possible implementation, S703 is performed after S702.

[0301] S703: The first communication device performs receive antenna channel sounding based on the second PPDU to obtain a second antenna selection feedback result.

[0302] At S703, the first communication device may receive multiple PPDUs sent by the second communication device based on different receive antenna sets to perform receive antenna channel sounding on the different receive antenna sets to obtain a second antenna selection feedback result.

[0303] In this embodiment of the present application, the first communication device that performs receive antenna channel sounding may be a device with antenna selection capability (ASEL), and the antenna selection capability transmitting end (e.g., the second communication device) may perform ASEL channel sounding by using an NDP sounding PPDU.

[0304] At S703, the first communication device may perform receive antenna channel sounding based on the received one or more PPDUs to obtain one or more receive antenna channel sounding results, and may select a receive antenna set based on the obtained receive antenna channel sounding results.

[0305] Further, the first communication device may indicate an identifier of the selected receive antenna set to the second communication device. For example, at S703, the first communication device may further add a second antenna selection feedback result in a sixth frame for sending. The first communication device sends the sixth frame. The sixth frame includes the second antenna selection feedback result. The second antenna selection feedback result includes a seventh identifier field. The seventh identifier field indicates the identifier of the first receive antenna set.

[0306] It should be noted that the seventh identifier field may carry the identifier of the receive antenna set selected by the first communication device. For example, if the receive antenna set selected by the first communication device is the first receive antenna set, the seventh identifier field may indicate the identifier of the first receive antenna set. In this embodiment of the present application, an example in which the receive antenna set selected by the first communication device is the first receive antenna set is used for presentation. In actual application, the first communication device may also select another receive antenna set (in this case, the seventh identifier field needs to indicate another receive antenna set). This is not limited in this embodiment of the present application.

[0307] In this embodiment of the present application, the selected transmitting antenna of the first communication device can be the same as or different from the selected receiving antenna of the first communication device. In other words, the first transmitting antenna set and the first receiving antenna set can be the same antenna set or different antenna sets. This is not limited in this embodiment of the present application.

[0308] Correspondingly, the second communication device receives the sixth frame from the first communication device.

[0309]

[0033] It should be noted that the first communication device may send the sixth frame or may not send the sixth frame. S403 is optional. The first communication device performs receive antenna channel sounding based on the second PPDU to obtain a second antenna selection feedback result, and receives data from the second communication device based on the selected first receive antenna set.

[0310] In a possible implementation, after S702, the first communication device may perform receive antenna channel sounding based on PPDUs from one or more second communication devices to obtain antenna selection feedback results. In S703, one second communication device is used as an example for explanation, and the solution for another second communication device is similar to the above solution for the second communication device. Details will not be described again.

[0311] It should be noted that the antenna selection feedback results corresponding to different second communication devices may be different or the same. This is not limited in this embodiment of the present application. Alternatively, it may be understood that the receive antenna sets of the first communication device corresponding to different second communication devices may be different or the same. This is not limited in this embodiment of the present application. For example, in FIG. 12, STA203 (second communication device) may select a first receive antenna set, and another second communication device may select the first receive antenna set or another receive antenna set.

[0312] From the above content, it can be learned that in this embodiment of the present application, since a fifth identifier field is added to the second PPDU, the first communication device can determine the identifier of the first receiving antenna set corresponding to the received second PPDU, and the first communication device can determine the received antenna channel sounding result obtained based on the NDP, which is the received antenna channel sounding result corresponding to the identifier of the first receiving antenna set. Thus, the first communication device can determine the identifier of the selected receiving antenna set based on one or more receiving antenna channel sounding results, and then receive data from the second communication device based on the receiving antenna set corresponding to the identifier of the selected receiving antenna set. Thus, antenna selection can be performed based on the antenna channel sounding result in a large antenna scenario.

[0313] Further description will be provided with reference to FIG. 12. At S702, the second communication device may send one or more PPDUs to the first communication device to be used by the first communication device to perform receive antenna channel sounding. Each PPDU may correspond to an antenna set of a group of receive antennas. The antenna set of each group of receive antennas is indicated by an antenna set identifier (in FIG. 12). identifier ,ID)) corresponds to one antenna set identifier.

[0314] The antenna set identifiers shown in FIG. 12 are antenna set IDs that are 0, 1, ..., and R. R can be a positive integer. It should be noted that there is no necessary relationship between the quantity of transmit antenna sets and the quantity of receive antenna sets of the first communication device, and the quantity of transmit antenna sets and the quantity of receive antenna sets can be the same or different. The (R+1) receive antenna sets shown in FIG. 12 are only an example. The PPDUs shown in FIG. 12 are denoted PPDU(j0), PPDU(j1), ..., and PPDU(j R ), as shown in FIG. 12, the second communication device sends PPDU(j0) by using a receive antenna set whose antenna set ID is 0. The first communication device performs receive antenna channel sounding based on PPDU(j0) to obtain a receive antenna channel sounding result corresponding to the receive antenna set whose antenna set ID is 0. Similarly, the second communication device sends PPDU(j1) by using a receive antenna set whose antenna set ID is 1, ..., and the second communication device sends PPDU(j2) by using a receive antenna set whose antenna set ID is R. R) The first communication device obtains receive antenna channel sounding results corresponding to receive antenna sets with antenna set IDs equal to 1, ..., and receive antenna channel sounding results corresponding to receive antenna sets with antenna set IDs equal to R. Furthermore, the first communication device may select a receive antenna set of the first communication device based on the R receive antenna channel sounding results, for example, select a first receive antenna set, and then receive data from the second communication device by using the first receive antenna set. Furthermore, the first communication device may further indicate the selected first receive antenna set to the second communication device.

[0315] The configuration of the antenna set identifiers in Figure 12 is just an example. During practical application, the antenna set identifiers of consecutive PPDUs received by the first communication device may be randomly, for example, non-sequentially configured, or not configured in ascending order. For example, the second communication device may consecutively receive PPDU(j1) from the second communication device by using a transmitting antenna set whose antenna set ID is 1, and receive PPDU(j2) from the second communication device by using a transmitting antenna set whose antenna set ID is R. R ), and receive PPDU(j0) from the second communication device by using the transmit antenna set with antenna set ID 0, and so on.

[0316] The following describes the relevant contents of the receive antenna set identifier described in this embodiment of the present application.

[0317] In a possible implementation, the second communication device includes k2 receive antenna sets. k2 is a positive integer. R in FIG. 12 may be a positive integer not greater than k2. R may be equal to or less than k2. The k2 receive antenna sets correspond one-to-one to the identifiers of the k2 receive antenna sets. In other words, one of the k2 receive antenna sets corresponds to one of the identifiers of the k2 receive antenna sets, and one of the identifiers of the k2 receive antenna sets corresponds to one of the k2 receive antenna sets. The identifiers of the two receive antenna sets corresponding to any two receive antenna sets may be different. The identifiers of the two receive antenna sets corresponding to any two receive antenna set identifiers may be different. The first receive antenna set is one of the k2 receive antenna sets. The following describes an example in which the first receive antenna set is used.

[0318] There are several implementations of the receive antenna set identifier, the descriptions of which are given separately as follows:

[0319] Implementation c1

[0320] In a possible implementation, the identifier of the first set of receive antennas may be the sequence number of the second PPDU corresponding to the first set of receive antennas.

[0321] In implementation c1, the fifth identifier field may indicate the rank of the second PPDU among the R PPDUs sent by the second communication device. 2It can be understood that when the PPDU sent by the first communication device is an NDP, the fifth identifier field can also indicate the rank of the current NDP among the R NDPs sent by the second communication device. In this way, the first communication device can determine a correspondence between the second PPDU and the antenna selection feedback result of the receive antennas based on the sequence number corresponding to the second PPDU indicated by the fifth identifier field. Thus, the first communication device can determine an identifier of a selected receive antenna set based on one or more receive antenna channel sounding results, and then receive data from the second communication device based on the receive antenna set corresponding to the identifier of the selected receive antenna set. Thus, antenna selection can be performed based on the antenna channel sounding result in a large antenna scenario.

[0322] Implementation c2

[0323] In another possible implementation, the identifier of the first receive antenna set may be a group identifier of the first receive antenna set. For the relevant content of the group identifier of the first receive antenna set, see the relevant content of the group identifier of the first transmit antenna set. For implementation c2, see implementation a2.

[0324] The identifier of the receive antenna set may further include the following possible implementations:

[0325] Implementation c2-1

[0326] The first communication device and the second communication device may perform negotiation. Through the negotiation, the first communication device may inform the second communication device of the total number of receive antenna sets supported by the first communication device. For example, the first communication device may send a tenth frame to the second communication device. The tenth frame includes eighth indication information. The eighth indication information indicates the total number of receive antenna sets supported by the first communication device. The tenth frame may be an MPDU. In this manner, the second communication device may estimate the overhead and duration of the receive antenna selection procedure based on the eighth indication information, and the second communication device may further determine whether to establish an association relationship with the first communication device based on the total number of receive antenna sets supported by the first communication device.

[0327] For implementation c2-1, please refer to implementation a2-1, and the details will not be described again in this specification.

[0328] Implementation c2-2

[0329] In this embodiment of the present application, the correspondence between the receive antenna sets and the group identifiers in the first communication device may be specified in advance (e.g., specified in a standard). The correspondence may be pre-configured in the first communication device or may be sent to the first communication device by another communication device. In this way, the first communication device can learn the receive antenna set identifiers of each receive antenna set, and the receive antenna set identifiers are therefore carried when the PPDU is sent.

[0330] For implementation c2-2, please refer to implementation a2-2, and the details will not be described again in this specification.

[0331] Implementation c2-3

[0332] The first communication device and the second communication device negotiate to determine a group identifier for the first set of receive antennas.

[0333] The first communication device and the second communication device may perform negotiation. The second communication device may learn receive antenna sets supported by the first communication device through the negotiation. After the negotiation, the first communication device and the second communication device may configure a group identifier for the receive antenna set supported by the first communication device. For example, the first communication device may send an eighth frame to the second communication device. The eighth frame may be an MPDU. The second communication device may receive the eighth frame. The eighth frame includes an eighth identifier field. The eighth identifier field indicates an identifier of at least one receive antenna set supported by the first communication device. The identifier of the at least one receive antenna set includes the identifier of the first receive antenna set.

[0334] In this way, the second communication device can learn the receive antenna set identifier of each receive antenna set, and the receive antenna set identifier is thus carried when the PPDU is sent. Furthermore, it can be seen that the second communication device can obtain more antenna set-related information through negotiation, and subsequently obtain more link-related information, thereby further providing assistance to another subsequent procedure.

[0335] For implementation c2-3, please refer to implementation a2-3, and the details will not be described again in this specification.

[0336] Note that implementations c1 and c2 may be implemented separately or in combination. For example, the identifier of the first receive antenna set may include the sequence number of the second PPDU corresponding to the first receive antenna set and the group identifier of the first receive antenna set. In this way, the first receive antenna set can be more accurately identified, and the flexibility of the solution may be improved.

[0337] In this embodiment of the present application, the identifier of the first receiving antenna set may be represented by one or more characters, or may be represented by one or more bits, for example, by one or more bits corresponding to a binary number. The information carried in the fifth identifier field includes all or some bits corresponding to the identifier of the first receiving antenna set. This implementation is similar to the related content of the first transmitting antenna set. For details, please refer to the related content of implementation b1 and implementation b2 of the first transmitting antenna set. The details will not be described again in this specification.

[0338] Based on the above content, Figure 13 is a schematic diagram of an example of signaling interaction of an antenna channel sounding method according to an embodiment of the present application. In Figure 13, S801, S802, and S803 are added with reference to Figure 12. Because the fifth frame in S701 of Figure 12 can be an NDPA frame or a second trigger frame, S701 can include two implementations of S801 and S803. After S801 or S803, the second communication device can perform S702, and the first communication device can perform S703. The following will further describe the frames in this embodiment of the present application with reference to the schematic diagram of signaling interaction shown in Figure 13.

[0339] As shown in FIG. 13, the method includes the following steps:

[0340] S801: The first communication device sends a second trigger frame.

[0341] The second trigger frame may be used to notify the second communication device that receive antenna selection needs to be performed.

[0342] S802: The second communication device sends a seventh frame, where the seventh frame includes sixth indication information, which is used to request receive antenna channel sounding.

[0343] Accordingly, the first communication device receives the seventh frame.

[0344] In this embodiment of the present application, the second communication device may send the seventh frame based on the trigger of the second trigger frame in S801, or may send the seventh frame by itself, which is not limited in this embodiment of the present application.

[0345] The following describes the relevant frame structure based on FIG. 13 and FIG.

[0346] In a possible implementation, in this embodiment of the present application, the fifth frame in S701 is the second trigger frame in S801. The second trigger frame may further include fourth indication information. The fourth indication information may be used to notify the second communication device that transmit antenna selection needs to be performed. Alternatively, the fourth indication information indicates that the second trigger frame is a receive antenna selection variant. The fifth frame may further include an amount of NDP and / or a sixth identifier field. The sixth identifier field indicates the identifier of the first receive antenna set.

[0347] 14A and 14B are schematic diagrams of an example of the structure of the second trigger frame. In yet another possible implementation, the amount of NDP and / or related information regarding receive antenna selection, such as a sixth identifier field, may be carried in some or all of the bits of at least one of the reserved bits of the common information field, the reserved bits of the user information list field, the trigger-dependent common information, or the trigger-dependent user information content.

[0348] From FIGS. 14A and 14B, in this embodiment of the present application, the existing trigger frameIt can be seen that the same structure can be used for the second trigger frame, and existing fields in the second trigger frame carry content related to receive antenna selection. As shown in Figures 14A and 14B, the second trigger frame can include a common information field and a user and information list field.

[0349] The common information fields are trigger type, uplink (UL) length, more trigger frames, carrier sense required, uplink (HE) bandwidth, guard interval (GI) + EHT long training sequence type (EHT-LTF Type), Multi-User Multiple-Input Multiple-Output (MU-MIMO) EHT-LTF mode, number of EHT-LTF symbols and midamble periodicity, uplink space-time block coding (UL STBC), low-density parity-check code (LDPC) extra symbol segment, AP transmit power, pre-FEC padding factor, and packet enhanced ambiguity removal (PE IR). Disambiguity, UL Spatial Reuse, Doppler, UL HE-SIG-A2 Reserved, Reserved, and trigger dependent common information content.

[0350] The reserved uplink HE-SIG-A2 (UL HE-SIG-A2 Reserved) includes the HE / EHT indication, the special user field presence indicator, and the other reserved uplink HE-SIG-A2 (other UL HE-SIG-A2 Reserved).

[0351] The User Information List field may include one or more pieces of user information, for example, User Information 1, User Information 2, ..., and User Information M in the figure. One or more pieces of user information may be special user information fields, or one or more pieces of user information may be EHT variant user information fields.

[0352] The special user information fields may include: Association Identifier (AID12) (=2007), Physical Version Identifier (physical version ID), Uplink EHT Bandwidth Extension (UL EHT BW Extension), Uplink EHT Spatial Reuse 1 (UL EHT Spatial Reuse 2), Universal Signaling Indicator (U-SIG) Disregard and Validate (U-SIG Disregard and Validate), Reserved, and Trigger Dependent User Info. In this embodiment of the present application, information may also be abbreviated as Info to indicate information.

[0353] The EHT variant user information fields (User Info 2 to M) may contain the following content: Association Identifier (AID12), Resource Unit Allocation (RU Allocation), UL forward error correction coding Type, UL EHT-modulation and coding scheme, reserved, spatial stream start value, quantity of spatial streams, UL target received signal strength indicator, PS160 primary / secondary 160 MHz indication, and trigger dependent user information.

[0354] Table 2 is a schematic diagram of an example of the meaning of the trigger type value of the second trigger frame shown in Figures 14A and 14B. From Table 2, it can be seen that in the current standard, values ​​8 to 15 are reserved for the trigger type of the second trigger frame. When the second trigger frame is selected as the fifth frame, the value of the trigger type of the second trigger frame can be selected from 8 to 15, and therefore, the value of the trigger type of the second trigger frame can indicate that the second trigger frame is used for receive antenna selection. The value of the trigger type of the second trigger frame can be used as a possible implementation of the fourth indication information.

[0355] [Table 2]

[0356] In S802, the seventh frame is a receive antenna selection sounding request. eThe seventh frame may be referred to as an antenna selection sounding request (SRS). The seventh frame may further include the amount of PPDUs requested to be sent by the second communication device. In this way, the first communication device may determine the amount of PPDUs that need to be subsequently sent by the second communication device based on the amount of PPDUs carried in the seventh frame, so that the amount of PPDUs that need to be subsequently sent by the second communication device and determined by the first communication device matches the requirements of the second communication device as closely as possible. The amount of PPDUs sent by the second communication device may be the same as or different from the amount of PPDUs requested in the seventh frame.

[0357] The seventh frame may be carried in an MPDU whose MAC frame header carries a High Throughput Control (HTC) field. The frame structure shown in FIG. 6 may be used as the frame structure of the seventh frame. The variant related to the seventh frame may be understood as a high-efficiency variant, or the sixth indication information may be carried in the high-efficiency variant field of the seventh frame. The sixth indication information is carried in at least one of a control identifier field, an antenna selection command field, or an antenna selection data field in the A-Control subfield. In this embodiment of the present application, a control ID value of the control identifier field that is not used in the standard may be used to indicate a receive antenna selection procedure. For example, the control ID value of the control identifier field may be 9 or one of 11 to 14. In this case, the length of the control information field may be up to 26 bits. When the seventh frame is an MPDU, please refer to the related description of FIG. 6 for related explanations and beneficial effects. Details will not be described again in this specification.

[0358] In S803, the first communication device may send an NDPA frame based on the seventh frame sent by the second communication device, or may send an NDPA frame by itself. This is not limited to this embodiment of the present application. In another possible implementation, the fifth frame in S701 may be an NDPA frame. In this case, the NDPA frame may be a frame including fourth indication information that indicates to the second communication device to perform receive antenna channel sounding.

[0359] The fifth frame (e.g., an NDPA frame) may further include an amount of NDP and / or a sixth identifier field, which indicates the identifier of the first receive antenna set.

[0360] In a possible implementation, when the NDPA frame includes a sixth identifier field, the sixth identifier field may include all bits corresponding to the identifier of the first receive antenna set. In this way, the fifth identifier field in a second PPDU subsequently sent by the second communication device may carry some bits corresponding to the identifier of the first receive antenna set, thus reducing the amount of bits occupied by the fifth identifier field in the second PPDU, and the first communication device may determine all bits of the identifier of the first receive antenna set corresponding to the second PPDU based on the sixth identifier field and the fifth identifier field.

[0361] FIG. 15 is a schematic diagram of an example of the structure of a fifth frame when the fifth frame is an NDPA frame. The sixth identifier field and the amount of NDP are not necessarily included in the NDPA frame. In FIG. 15, an example in which the fifth frame includes the sixth identifier field, the amount of NDP, and the fourth indication information is used for presentation. The difference between the structure of the NDPA frame shown in FIG. 15 and the structure of the NDPA frame shown in FIG. 7 is in the structure of FIG. 15, where an example in which the identifier of the receive antenna set is included and an example in which the association identifier field is 2043 is used for presentation. For other contents and beneficial effects, please refer to the description of FIG. 7.

[0362] Similarly, in this embodiment of the present application, a specific association identifier in the station information field may indicate that the information in the station information field is antenna selection-related information. For example, at least one of the fourth indication information, the amount of NDP, or the sixth identifier field is for the fifth frame and is carried in at least one station information field including the fifth indication information. The fifth indication information indicates that the station information field includes antenna selection-related information. In this way, when the fifth indication information is identified, the second communication device may determine that the station information field carrying the fifth indication information carries antenna selection-related information and then obtain the antenna selection-related information from the station information field. The fifth indication information may distinguish the station information field carrying antenna selection-related information from a station information field corresponding to another conventional station. Therefore, in a solution in which the station information field carries antenna selection-related information, the station information field corresponding to the conventional station is not affected, and compatibility with existing standards is achieved.

[0363] Similar to FIG. 7 , the fifth indication information may be carried in an association identifier field in the station information field. The fifth indication information may include one of 2008 to 2043 or 2046. In this manner, the second communication device may determine, based on the association identifier field, whether the station information field carries antenna selection-related information or station information corresponding to another second communication device. It may be appreciated that this solution may better fit with conventional techniques. The fourth indication information may also be referred to as an antenna selection type, antenna selection NDPA variant indication information, or NDPA frame variant subtype. The fourth indication information further indicates that the variant of the NDPA frame is an antenna selection variant.

[0364] From the 802.11ax standard to the 802.11be standard, the NDPA frame with the HT control field is no longer supported. In this embodiment of the present application, corresponding antenna selection related information is carried in the station information field, so that the information required for antenna selection can be indicated. Furthermore, the association identifier in the association identifier field of the station information field is a special association identifier, and the content of the station information field can be read by multiple second communication devices.

[0365] In S702, the second PPDU sent by the second communication device may not include a data field, for example, an NDP, or may include a data field.

[0366] When the second PPDU does not include a data field, the structure of the second PPDU may be the NDP structure shown in Figure 8a or 8b. When the second PPDU is the NDP shown in Figure 8a or 8b, the fifth identifier field is located in the preamble of the second PPDU. For example, the fifth identifier field may include some or all of the bits in the U-SIG and / or some or all of the bits in the EHT-SIG. For related content, please refer to the descriptions of Figures 8a and 8b. Details will not be described again.

[0367] In another possible implementation, when the second PPDU does not include a data field, the structure of the second PPDU may be as shown in the schematic diagram of the NDP structure shown in Figure 16a or Figure 16b. Figures 16a and 16b are schematic diagrams of two types of second PPDU structures in which the second PPDU is an NDP. Compared to Figure 8a, Figure 16a does not have an EHT-SIG field. For other fields, please refer to the related description of Figure 8a. Compared to Figure 8b, Figure 16b does not have an NG-SIG field. For other fields, please refer to the related description of Figure 8b. When the second PPDU is the NDP shown in Figure 16a or Figure 16b, the fifth identifier field is located in the preamble of the second PPDU. For example, the fifth identifier field may include some or all of the bits in the U-SIG. For example, one or more bits in B20 to B24 of the first symbol of the U-SIG and B25 of the first symbol of the U-SIG field may be used as the fifth identifier field.

[0368] When the second PPDU includes a data field, the structure of the second PPDU may be as shown in the frame structure diagram of Figure 8c. When the second PPDU is the frame shown in Figure 8c, the fifth identifier field is located in the preamble of the second PPDU. For example, the fifth identifier field may include some or all of the bits of at least one of the U-SIG, EHT-SIG, or data field. For related content, please refer to the descriptions of Figures 8a and 8b. Details will not be described again.

[0369] In another possible implementation, when the second PPDU includes a data field, the structure of the second PPDU may be as shown in the schematic diagram of the frame structure shown in Figure 16c. Figure 16c is a schematic diagram of an example of the structure of a second PPDU including a data field. Compared to Figure 8c, Figure 16c does not include an NG-SIG field. For other fields, please refer to the related description of Figure 8c. When the second PPDU has the frame structure shown in Figure 16c, the fifth identifier field is located in the preamble of the second PPDU. For example, the fifth identifier field may include some or all of the bits in at least one of the U-SIG or data fields. For related content, please refer to the above description. Details will not be described again.

[0370] In S703, the sixth frame may be a beamforming report frame, and the frame structure may be the frame structure shown in Figure 9. For related descriptions, please refer to the related descriptions of Figure 9. The following will describe the sixth frame with reference to Figure 9.

[0371] The sixth frame is the MIMO control OfuThe seventh identifier field may include a seventh identifier field. The seventh identifier field may include some or all of the bits in the MIMO control field. The seventh identifier field includes all bits corresponding to the identifier of the first receive antenna set. In this way, the second communication device may determine that the receive antenna set selected by the first communication device is the first receive antenna set based on the seventh identifier field in the sixth frame.

[0372] In a possible implementation, the seventh identifier field may include two parts: an antenna set identifier field and a sounding PPDU sequence number field. The antenna set identifier field may carry a group identifier of the first receive antenna set, and the sounding PPDU sequence number field may carry a sequence number of the second PPDU corresponding to the first receive antenna set.

[0373] In another possible implementation, the sixth frame may further include an antenna selection failure feedback field. In yet another possible implementation, the sixth frame may further include at least one of a compressed beamforming report, a multi-user specific beamforming report, and a channel quality status report. For example, the channel quality status report may include at least one of channel state information (CSI) or channel quality information (CQI) corresponding to the PPDU.

[0374] One or more of the compressed beamforming report, the multi-user specific beamforming report, and the channel quality status report may be carried in a field other than the MIMO control field in the sixth frame. Of course, at least one of the antenna set identifier field and the sounding PPDU sequence number field included in the seventh identifier field may alternatively be set in another field. For example, the sounding PPDU sequence number field may be located in the A-control subfield. For other contents of the sixth frame, please refer to the related description of Figure 9. Details will not be described again in this specification.

[0375] From the above content, it can be learned that in this embodiment of the present application, for example, when the NDPA frame does not support a high-throughput control field, an antenna selection procedure for receiving antennas is designed based on NDPA (the fifth frame) + NDP (PPDU) + feedback (the sixth frame). The antenna selection procedure can be consistent with the current channel sounding procedure, and the devices at the receiving end and the transmitting end are slightly modified, and the implementation is simple.

[0376] Based on the above content, FIG. 17 is a schematic diagram of an example of signaling interaction of an antenna channel sounding method according to an embodiment of the present application.

[0377] 17, the interaction between the first communication device and the second communication device is used as an example for presentation. In this embodiment of the present application, the first communication device may be referred to as an antenna selection transmitter, and the second communication device may be referred to as an antenna selection responder.

[0378] The first communication device in Figure 17 may be the first communication device in Figure 1, may be the AP or STA in Figure 2, or may be the communication device in Figure 3. The second communication device in Figure 17 may be the second communication device in Figure 1, may be the AP or STA in Figure 2, or may be the communication device in Figure 3. The first communication device and the second communication device in Figure 17 may both be APs, both be STAs, or an AP and a STA, respectively. In Figure 17, an example in which the first communication device is an AP and the second communication device is a STA is used for presentation.

[0379] The solution provided in this embodiment of the present application is applicable to a receive antenna channel sounding procedure between an AP and a single STA, or to a receive antenna channel sounding procedure between an AP and multiple STAs. Figure 17 is a schematic diagram of an example in which a receive antenna channel sounding procedure is performed between an AP and multiple STAs (for example, STA203, STA204, and STA205 in Figure 17).

[0380] It should be noted that the solution given in Figure 17 is used to select a receive antenna in the first communication device. The solutions given in Figures 4 and 10 are used to select a transmit antenna in the first communication device. The solution in Figure 17 may be used in combination with the solution in Figure 4 or Figure 10, or may be implemented independently. The solution in Figure 4 or Figure 10 may also be implemented independently, or may be used in combination with the solution in Figure 17. When the solutions in Figures 4 and 17 are used in combination, the first communication device may select a transmit antenna according to the solution in Figure 4 and a receive antenna according to the solution in Figure 17. When the solutions in Figures 10 and 17 are used in combination, the first communication device may select a transmit antenna according to the solution in Figure 10 and a receive antenna according to the solution in Figure 17.

[0381] As shown in FIG. 17, the method includes the following steps:

[0382] S901: A first communication device sends a 12th frame to a second communication device, the 12th frame including fourth indication information, and the fourth indication information indicates to the second communication device to perform receive antenna channel sounding.

[0383] Correspondingly, the second communication device receives the twelfth frame from the first communication device.

[0384] S902: The second communication device sends a fourth PPDU to the first communication device, where the fourth PPDU is used to perform receive antenna channel sounding.

[0385] Correspondingly, the first communication device receives a fourth PPDU from the second communication device.

[0386] The fourth PPDU may include M2 ​​second information fields corresponding to the M2 receive antenna sets, where M2 is an integer greater than 1. The second information fields are used to perform receive antenna channel sounding.

[0387] S903: The first communication device performs receive antenna channel sounding based on the second PPDU to obtain a second antenna selection feedback result.

[0388] Further, in S903, the first communication device may further feed back a second antenna selection feedback result to the second communication device.

[0389] In this embodiment of the present application, it can be learned from the solution that the second communication device can aggregate PPDUs corresponding to M2 receive antenna sets that need to be sent in S902 into one PPDU to reduce overhead, improve antenna selection efficiency, and improve system throughput.

[0390] 18 and 19 are schematic diagrams of examples of frame structures of two types of fourth PPDUs, respectively. Compared with FIG. 18, FIG. 19 does not include an EHT-SIG field.

[0391] 18 and 19, the fourth PPDU may include M2 ​​second information fields corresponding to the M2 receive antenna sets, where M2 may be an integer greater than 1. The second information fields are used to perform receive antenna channel sounding.

[0392] The second information field includes at least one of an EHT short training field, an EHT long training field, and a packet extension field. Any two second information fields use different receive antenna sets. For example, the three receive antenna sets shown in Figure 18 are the second information field corresponding to the receive antenna set with antenna set ID 0, the second information field corresponding to the receive antenna set with antenna set ID 1, ..., and the second information field corresponding to the receive antenna set with antenna set ID M2, respectively.

[0393] As shown in Figure 18, the fourth PPDU may further include a preamble. The preamble includes at least one of the fields L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, or EHT-SIG. As shown in Figure 19, the fourth PPDU may further include a preamble. The preamble includes at least one of the fields L-STF, L-LTF, L-SIG, RL-SIG, or U-SIG. For related descriptions of the preamble, please refer to the related description of Figure 16a. Details will not be described again in this specification.

[0394] From Figures 18 and 19, it can be seen that at S902, M2 PPDUs corresponding to the M2 receive antenna sets that originally need to be sent are aggregated into one fourth PPDU, and therefore (M2-1) preambles can be reduced.

[0395] Furthermore, it can be seen from FIG. 18 that each second information field may include one packet extension field, for example, packet extension 0 in the second information field corresponding to antenna set ID=0 shown in FIG. 18, packet extension 1 in the second information field corresponding to antenna set ID=1 shown in FIG. 18, ..., and packet extension M2 in the second information field corresponding to antenna set ID=M2 shown in FIG. 18. The duration of any two data extensions in the packet extensions (packet extension 0 to packet extension (M2-1)) other than the last packet extension M2 may be the same. The duration of these packet extension fields may be used to provide more processing time to the second communication device. Furthermore, time may be provided for antenna switching by the first communication device. Furthermore, the duration may be set to a shorter value, sufficient for antenna switching by the first communication device.

[0396] In a possible implementation, the durations of the packet extension fields in at least two of the M2 second information fields may be different. For example, the duration of packet extension M2 may be different from the duration of packet extension 1. The duration of packet extension M2 may be set to a slightly longer value. The duration of packet extension 1 may be set to a slightly shorter value, sufficient for antenna switching by the first communication device. Furthermore, in this implementation, the durations of any two data extensions in a packet extension other than the last packet extension M2 (packet extension 0 to packet extension (M2-1)) may be the same or different.

[0397] In another possible implementation, the duration of the packet extension field in any two of the M2 second information fields is the same. In this way, the consistency of the reception procedure can be improved.

[0398] Compared with the solution in which the second communication device transmits PPDUs corresponding to M2 receive antennas, the solution shown in FIG. 18 requires only one fourth PPDU to transmit M2 groups of information used for receiving antenna channel sounding. In this solution, the number of preambles (L-STF to EHT-SIG) and the number of short interframe spaces (SIFS) in (M2-1) groups can be reduced. When any two times from packet extension 0 to packet extension (M2-1) are equal and the duration of packet extension 0 is shorter than the duration of packet extension M2, the time difference between packet extension M2 and packet extension 0 can be further reduced.

[0399] For example, the preamble (L-STF to EHT-SIG) in the fourth PPDU lasts a total of 36 microseconds, the duration of packet extension M2 is 16 microseconds, and the SIFS lasts 16 microseconds. If the duration of any one of packet extensions 0 to (M2-1) is 4 microseconds, and M2=64, then compared to transmitting a PPDU corresponding to M2 receive antennas (where the PPDU includes a preamble and one second information field, and the data extension field contained in the second information field is 16 microseconds), in this case, 36×(64−1)+16×(64−1)+(16−4)×(64−1)=4032 microseconds can be saved by transmitting the fourth PPDU.

[0400] It should be noted that FIG. 18 is only one example of a possible frame structure of the fourth PPDU. In this example, the EHT-SIG is transmitted once. In yet another possible implementation, the EHT-SIG may appear in a group. For example, each second information field includes one EHT-SIG. Furthermore, in FIG. 17, an example in which the second communication device transmits one fourth PPDU is used for presentation. During actual application, in S902, the second communication device may send one or more fourth PPDUs, and the amount of the second information field included in the fourth PPDU may be the same or different.

[0401] Furthermore, it should be noted that Figure 17 provides an implementation in which PPDUs sent by the second communication device may be aggregated in this embodiment of the present application. This implementation may be used in combination with the antenna selection solution provided in Figure 12 or Figure 13, or may be implemented independently. The 12th frame in S901 may be an NDPA frame in this embodiment of the present application.

[0402] When this implementation is used in combination, please refer to the relevant content of S701 for the relevant content of S901, and refer to the relevant description of the fifth frame for the relevant content of the twelfth frame. For the relevant content of S903, please refer to the relevant content of S703. For the relevant content of the antenna selection feedback result, please refer to the relevant description of the sixth frame. When this implementation is used in combination, the amount of NDP described in FIG. 12 or FIG. 13 may be equal to the amount of the second information field described in FIG. 17. When this implementation is used in combination, please refer to the structure of the fourth PPDU for the structure of the second PPDU. In other words, the second PPDU may also include second information fields corresponding to multiple receive antenna sets. For example, the second PPDU includes a second information field corresponding to the first receive antenna and further includes a second information field corresponding to the second receive antenna. The first PPDU includes one preamble. Furthermore, a U-SIG in the preamble may be disposed in each second information field. A fifth identifier field may be carried in each second information field.

[0403] It can be understood that to implement the functions in the above embodiments, the communication device includes corresponding hardware structures and / or software modules for performing the functions. Those skilled in the art should easily recognize that the units and method steps in the examples described with reference to the embodiments disclosed in this application can be implemented by hardware or a combination of hardware and computer software. Whether the functions are performed by hardware or by hardware driven by computer software depends on the specific application scenario and the design constraints of the technical solution.

[0404] 20, 21, and 22 are schematic diagrams of possible communication device structures according to an embodiment of the present application. The communication devices may be configured to implement the functions of the first communication device in the above method embodiments, and thus may also implement the beneficial effects of the above method embodiments. Alternatively, these communication devices may be configured to implement the functions of the second communication device in the above method embodiments, and thus may also implement the beneficial effects of the above method embodiments. In these embodiments of the present application, the communication devices may be the transmitting device or first communication device of FIG. 1, 2, 3, 4, 5, 10, 12, 13, or 17, or may be a module (e.g., a chip) applied to the transmitting device or first communication device. In these embodiments of the present application, the communication devices may be the receiving device or second communication device of FIG. 1, 2, 3, 4, 5, 10, 12, 13, or 17, or may be a module (e.g., a chip) applied to the receiving device or second communication device.

[0405] 20, the communication device 1300 includes a processing unit 1310 and a transceiver unit 1320. The communication device 1300 is configured to implement the functionality of the first communication device in the method embodiments shown in FIG. 4, FIG. 5, FIG. 10, FIG. 12, FIG. 13, or FIG. 17.

[0406] When the communication device 1300 is configured to implement the functionality of the first communication device in the method embodiment shown in FIG. 4 or 5, the processing unit 1310 is configured to send a first frame to a second communication device and send a first PPDU to the second communication device by using the transceiver unit 1320. The first frame includes first indication information. The first indication information indicates to the second communication device to perform transmit antenna channel sounding. The first PPDU is an NDP. The first PPDU is used by the second communication device to perform transmit antenna channel sounding. The first PPDU includes a first identifier field. The first identifier field indicates an identifier of a first transmit antenna set.

[0407] When the communication device 1300 is configured to implement the functionality of the first communication device in the method embodiment shown in FIG. 4 or 5, the processing unit 1310 is further configured to receive a second frame from the second communication device by using the transceiver unit 1320. The second frame includes a first antenna selection feedback result. The first antenna selection feedback result includes a third identifier field. The third identifier field indicates an identifier of the first transmit antenna set.

[0408] When the communications device 1300 is configured to implement the functionality of the first communications device in the method embodiment shown in FIG. 4 or 5, the processing unit 1310 is configured to send a fourth frame to the second communications device by using the transceiver unit 1320. The fourth frame includes a fourth identifier field. The fourth identifier field indicates an identifier of at least one transmit antenna set supported by the first communications device. The identifier of the at least one transmit antenna set includes the identifier of the first transmit antenna set.

[0409] 4 or 5, the processing unit 1310 is configured to send a ninth frame to the second communication device by using the transceiver unit 1320. The ninth frame includes seventh indication information. The seventh indication information indicates a total amount of transmit antenna sets supported by the first communication device.

[0410] When the communication device 1300 is configured to implement the functionality of the first communication device in the method embodiment shown in FIG. 10 , the processing unit 1310 is configured to send an eleventh frame to the second communication device by using the transceiver unit 1320. The eleventh frame includes first indication information. The first indication information indicates to the second communication device to perform transmit antenna channel sounding. The first communication device sends a third PPDU to the second communication device. The third PPDU is used by the second communication device to perform transmit antenna channel sounding. The third PPDU includes M1 first information fields corresponding to M1 transmit antenna sets, where M1 is an integer greater than 1. The first information field is used to perform transmit antenna channel sounding. The first information field includes at least one of an EHT short training field, an EHT long training field, and a packet extension field.

[0411] When the communication device 1300 is configured to implement the functionality of the first communication device in the method embodiment shown in FIG. 12 or 13 , the processing unit 1310 is configured to send a fifth frame to a second communication device and receive a second PPDU from the second communication device by using the transceiver unit 1320. The fifth frame includes fourth indication information. The fourth indication information indicates to the first communication device that receive antenna channel sounding is to be performed. The second PPDU to the first communication device is an NDP. The second PPDU is used by the first communication device to perform receive antenna channel sounding. The second PPDU includes a fifth identifier field. The fifth identifier field indicates an identifier of the first receive antenna set.

[0412] When the communication device 1300 is configured to implement the functionality of the first communication device in the method embodiment shown in FIG. 17, the processing unit 1310 is configured to send a twelfth frame to the second communication device by using the transceiver unit 1320 and receive a fourth PPDU from the second communication device. The twelfth frame includes fourth indication information. The fourth indication information indicates to the first communication device that receive antenna channel sounding is to be performed. The fourth PPDU is used by the second communication device to perform receive antenna channel sounding. PD U includes M2 second information fields corresponding to the M2 receive antenna sets, where M2 is an integer greater than 1. The second information fields are used to perform receive antenna channel sounding. The second information fields include at least one of an EHT short training field, an EHT long training field, and a packet extension field.

[0413] 20, the communication device 1300 includes a processing unit 1310 and a transceiver unit 1320. The communication device 1300 is configured to implement the functionality of the second communication device in the method embodiments shown in FIG. 4, FIG. 5, FIG. 10, FIG. 12, FIG. 13, or FIG. 17.

[0414] When the communication device 1300 is configured to implement the functionality of the second communication device in the method embodiment shown in FIG. 4 or 5, the processing unit 1310 is configured to receive a first frame from the first communication device by using the transceiver unit 1320 and receive a first PPDU from the first communication device. The first frame includes first indication information. The first indication information indicates to the second communication device to perform transmit antenna channel sounding. The first PPDU is an NDP. The first PPDU is used by the second communication device to perform transmit antenna channel sounding. The first PPDU includes a first identifier field. The first identifier field indicates an identifier of a first transmit antenna set.

[0415] When the communication device 1300 is configured to implement the functionality of the second communication device in the method embodiment shown in FIG. 4 or 5, the processing unit 1310 is further configured to: perform transmit antenna channel sounding based on the first PPDU by using the transceiver unit 1320 to obtain a first antenna selection feedback result; and send a second frame by using the transceiver unit 1320. The second frame includes the first antenna selection feedback result. The first antenna selection feedback result includes a third identifier field. The third identifier field indicates an identifier of the first transmit antenna set.

[0416] When the communication device 1300 is configured to implement the functionality of the second communication device in the method embodiment shown in FIG. 4 or 5, the processing unit 1310 is particularly configured to receive a fourth frame from the first communication device by using the transceiver unit 1320. The fourth frame includes a fourth identifier field. The fourth identifier field indicates an identifier of at least one transmit antenna set supported by the first communication device. The identifier of the at least one transmit antenna set includes the identifier of the first transmit antenna set.

[0417] 4 or 5, the processing unit 1310 is particularly configured to receive a ninth frame from the first communication device by using the transceiver unit 1320. The ninth frame includes seventh indication information. The seventh indication information indicates a total amount of transmit antenna sets supported by the first communication device.

[0418] When the communication device 1300 is configured to implement the functionality of the second communication device in the method embodiment shown in FIG. 10 , the processing unit 1310 is configured to receive an eleventh frame from the first communication device by using the transceiver unit 1320 and receive a third PPDU from the first communication device. The eleventh frame includes first indication information. The first indication information indicates to the second communication device to perform transmit antenna channel sounding. The third PPDU is used by the second communication device to perform transmit antenna channel sounding. The third PPDU includes M1 first information fields corresponding to M1 transmit antenna sets, where M1 is an integer greater than 1. The first information field is used to perform transmit antenna channel sounding. The first information field includes at least one of an EHT short training field, an EHT long training field, and a packet extension field.

[0419] When the communications device 1300 is configured to implement the functionality of the second communications device in the method embodiment shown in FIG. 12 or 13 , the processing unit 1310 is configured to: receive a fifth frame from the first communications device by using the transceiver unit 1320, the fifth frame including fourth indication information, the fourth indication information indicating to the first communications device to perform receive antenna channel sounding; and send a second PPDU to the first communications device by using the transceiver unit 1320. The second PPDU is a null data packet (NDP). The second PPDU is used by the first communications device to perform receive antenna channel sounding. The second PPDU includes a fifth identifier field. The fifth identifier field indicates an identifier of the first receive antenna set.

[0420] When the communication device 1300 is configured to implement the functionality of the second communication device in the method embodiment shown in FIG. 17 , the processing unit 1310 is configured to: receive a twelfth frame from the first communication device by using the transceiver unit 1320, the twelfth frame including fourth indication information, the fourth indication information indicating to the first communication device to perform receive antenna channel sounding; and send a fourth PPDU to the first communication device by using the transceiver unit 1320. The fourth PPDU is used by the second communication device to perform receive antenna channel sounding. The fourth PPDU includes M2 second information fields corresponding to M2 receive antenna sets, where M2 is an integer greater than 1. The second information field is used to perform receive antenna channel sounding. The second information field includes at least one of an EHT short training field, an EHT long training field, and a packet extension field.

[0421] For a more detailed description of the processing unit 1310 and the transceiver unit 1320, please directly refer to the relevant descriptions in the method embodiments shown in Figure 4, Figure 5, Figure 10, Figure 12, Figure 13, or Figure 17. The details will not be described again here.

[0422] 21 , the communication device 1400 includes a processing circuit 1410 and an interface circuit 1420. The processing circuit 1410 and the interface circuit 1420 are coupled to each other. It may be understood that the interface circuit 1420 may be a transceiver or an input / output interface. Optionally, the communication device 1400 may further include a memory configured to store instructions to be executed by the processing circuit, or to store input data required by the processing circuit 1410 to execute the instructions, or to store data generated after the processing circuit 1410 executes the instructions.

[0423] When the communication device 1400 is configured to implement the method shown in FIG. 4, FIG. 5, FIG. 10, FIG. 12, FIG. 13, or FIG. 17, the processing circuit 1410 is configured to implement the functions of the processing unit 1310, and the interface circuit 1420 is configured to implement the functions of the transceiver unit 1320.

[0424] 22 , the communication device 1500 includes a processor 1510 and a communication interface 1520. The processor 1510 and the communication interface 1520 are coupled to each other. It may be understood that the communication interface 1520 may be a transceiver or an input / output interface. Optionally, the communication device 1500 may further include a memory 1530 configured to store instructions to be executed by the processor 1510, or to store input data required by the processor 1510 to execute the instructions, or to store data generated after the processor 1510 executes the instructions.

[0425] When the communication device 1500 is configured to implement the method shown in FIG. 4, FIG. 5, FIG. 10, FIG. 12, FIG. 13, or FIG. 17, the processor 1510 is configured to implement the functions of the processing unit 1310, and the communication interface 1520 is configured to implement the functions of the transceiver unit 1320.

[0426] When the communication device 1500 is configured to implement the functionality of the first communication device in the method embodiment shown in FIG. 4 or 5, the processor 1510 is configured to: send a first frame to a second communication device by using the communication interface 1520, the first frame including first indication information, the first indication information indicating to the second communication device to perform transmit antenna channel sounding; and send a first PPDU to the second communication device by using the communication interface 1520. The first PPDU is a null data packet (NDP). The first PPDU is used by the second communication device to perform transmit antenna channel sounding. The first PPDU includes a first identifier field. The first identifier field indicates an identifier of a first transmit antenna set.

[0427] When the communication device 1500 is configured to implement the functionality of the first communication device in the method embodiment shown in FIG. 10 , the processor 1510 is configured to: send an eleventh frame to a second communication device by using the communication interface 1520, the eleventh frame including first indication information, the first indication information indicating to the second communication device to perform transmit antenna channel sounding; and send a third PPDU to the second communication device by using the communication interface 1520. The third PPDU is used by the second communication device to perform transmit antenna channel sounding. The third PPDU includes M1 first information fields corresponding to M1 transmit antenna sets, where M1 is an integer greater than 1. The first information field is used to perform transmit antenna channel sounding. The first information field includes at least one of an EHT short training field, an EHT long training field, and a packet extension field.

[0428] When the communications device 1500 is configured to implement the functionality of the first communications device in the method embodiment shown in FIG. 12 or 13 , the processor 1510 is configured to: send a fifth frame to the second communications device by using the communications interface 1520, the fifth frame including fourth indication information, the fourth indication information indicating to the first communications device to perform receive antenna channel sounding; and receive a second physical layer protocol data unit (PPDU) from the second communications device by using the communications interface 1520. The second PPDU is a null data packet (NDP). The second PPDU is used by the first communications device to perform receive antenna channel sounding. The second PPDU includes a fifth identifier field. The fifth identifier field indicates an identifier of the first receive antenna set.

[0429] 17, the processor 1510 is configured to: send a twelfth frame to the second communication device by using the communication interface 1520, the twelfth frame including fourth indication information, the fourth indication information indicating to the first communication device to perform receive antenna channel sounding; and receive a fourth physical layer protocol data unit (PPDU) from the second communication device by using the communication interface 1520. The fourth PPDU is used by the second communication device to perform receive antenna channel sounding. PD U includes M2 second information fields corresponding to the M2 receive antenna sets, where M2 is an integer greater than 1. The second information fields are used to perform receive antenna channel sounding. The second information fields include at least one of an EHT short training field, an EHT long training field, and a packet extension field.

[0430] When the communication device 1500 is configured to implement the functionality of the second communication device in the method embodiment shown in FIG. 4 or 5, the processor 1510 is configured to: receive a first frame from the first communication device by using the communication interface 1520, the first frame including first indication information, the first indication information indicating to the second communication device to perform transmit antenna channel sounding; and receive a first physical layer protocol data unit (PPDU) from the first communication device by using the communication interface 1520. The first PPDU is a null data packet (NDP). The first PPDU is used by the second communication device to perform transmit antenna channel sounding. The first PPDU includes a first identifier field. The first identifier field indicates an identifier of a first transmit antenna set.

[0431] The communication device 1500 is a first 2When configured to implement the functionality of the communication device of the present invention, the processor 1510 is configured to: receive an eleventh frame from a first communication device by using the communication interface 1520, the eleventh frame including first indication information, the first indication information indicating to a second communication device to perform transmit antenna channel sounding; and receive a third physical layer protocol data unit (PPDU) from the first communication device by using the communication interface 1520. The third PPDU is used by the second communication device to perform transmit antenna channel sounding. The third PPDU includes M1 first information fields corresponding to M1 transmit antenna sets, where M1 is an integer greater than 1. The first information field is used to perform transmit antenna channel sounding. The first information field includes at least one of an EHT short training field, an EHT long training field, and a packet extension field.

[0432] When the communication device 1500 is configured to implement the functionality of the second communication device in the method embodiment shown in FIG. 12 or 13, the processor 1510 is configured to: receive a fifth frame from the first communication device by using the communication interface 1520, the fifth frame including fourth indication information, the fourth indication information indicating to the first communication device to perform receive antenna channel sounding; and send a second physical layer protocol data unit (PPDU) to the first communication device by using the communication interface 1520. The second PPDU is a null data packet (NDP). The second PPDU is used by the first communication device to perform receive antenna channel sounding. The second PPDU includes a fifth identifier field. The fifth identifier field indicates an identifier of the first receive antenna set.

[0433] When the communication device 1500 is configured to implement the functionality of the second communication device in the method embodiment shown in FIG. 17 , the processor 1510 is configured to: receive a twelfth frame from the first communication device by using the communication interface 1520, the twelfth frame including fourth indication information, the fourth indication information indicating to the first communication device to perform receive antenna channel sounding; and send a fourth physical layer protocol data unit (PPDU) to the first communication device by using the communication interface 1520. The fourth PPDU is used by the second communication device to perform receive antenna channel sounding. The fourth PPDU includes M2 second information fields corresponding to M2 receive antenna sets, where M2 is an integer greater than 1. The second information field is used to perform receive antenna channel sounding. The second information field includes at least one of an EHT short training field, an EHT long training field, and a packet extension field.

[0434] When the communication device is a chip used in the communication device, the chip in the communication device implements the functions of the communication device in the above method embodiments. The chip in the communication device receives information from another module (e.g., a radio frequency module or an antenna) in the communication device, and the information is sent to the communication device by a network device, or the chip in the communication device sends information to another module (e.g., a radio frequency module or an antenna) in the communication device, and the information is sent to the network device by the communication device.

[0435] It may be understood that the processor in the embodiments of the present application may be a Central Processing Unit (CPU), or may be another general-purpose processor, a Digital Signal Processor (DSP), an Application-Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. A general-purpose processor may be a microprocessor, any conventional processor, etc.

[0436] According to the method provided in the present application, an embodiment of the present application further provides a computer program product. The computer program product includes a computer program or instructions. When the computer program or instructions are executed on a computer, the computer can perform the method in any one of the embodiments shown in Figure 4, Figure 5, Figure 10, Figure 12, Figure 13, or Figure 17.

[0437] According to the method provided in the embodiments of the present application, the present application further provides a computer-readable storage medium. The computer-readable medium stores a program or instruction. When the program or instruction is executed on a computer, the computer can perform the method in any one of the embodiments shown in Figure 4, Figure 5, Figure 10, Figure 12, Figure 13, or Figure 17.

[0438] According to the method provided in the embodiments of the present application, the present application further provides a chip system. The chip system may include a processing circuit and an interface circuit. The processing circuit may use the interface circuit to implement the method in any one of the embodiments shown in Figures 4, 5, 10, 12, 13, or 17. Optionally, the chip system further includes a memory. The memory is configured to store a computer program (sometimes referred to as code or instructions). The processing circuit may be configured to call the computer program from the memory and execute the computer program, so that a device having the chip system installed therein implements the method in any one of the embodiments shown in Figures 4, 5, 10, 12, 13, or 17.

[0439] According to the method provided in the embodiment of the present application, the present application further provides a system including the above first communication device and the above second communication device.

[0440] The method steps in the embodiments of the present application may be implemented in a hardware manner or by a processor executing software instructions. The software instructions may include corresponding software modules. The software modules may be stored in a random access memory (RAM), a flash memory, a read-only memory (ROM), a programmable read-only memory, an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory, a register, a hard disk, a solid-state drive (SSD), a removable hard disk, a compact disc read-only memory (CD-ROM), or any other form of storage medium well known in the art. For example, the storage medium may be coupled to the processor, such that the processor can read information from and write information to the storage medium. Of course, the storage medium may be a component of the processor. The processor and the storage medium may be disposed in an ASIC. Furthermore, the ASIC may be located in a communication device. Of course, the processor and the storage medium may reside as discrete components in a communications device.

[0441] All or part of the above embodiments may be implemented using software, hardware, firmware, or any combination thereof. When software is used to implement an embodiment, all or part of the embodiment may be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, all or part of the procedures or functions in the embodiments of the present application are performed. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or another programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer program or instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center via a wired or wireless method. The computer-readable storage medium may be any available medium accessible by a computer or a data storage device, such as a server or data center, that incorporates one or more available media. The available media may be magnetic media, such as floppy disks, hard disks, or magnetic tapes, or optical media, such as digital video disks, or semiconductor media, such as solid-state drives. The computer-readable storage media may be volatile or nonvolatile storage media, or may include both volatile and nonvolatile storage media.

[0442] In various embodiments of the present application, unless otherwise specified or there is no logical conflict, the terms and / or descriptions in different embodiments are consistent and may be cross-referenced, and the technical features in different embodiments may be combined based on their internal logical relationships to form new embodiments.

[0443] In this application, "plurality" refers to two or more than two. The term "and / or" represents an association relationship between related objects and indicates that three relationships may exist. For example, A and / or B may represent three cases: only A is present, both A and B are present, and only B is present, where A and B may be singular or plural. In the text descriptions of this application, the character " / " indicates an "or" relationship between related objects. In the formulas of this application, the character " / " indicates a "divide by" relationship between related objects. "Comprising at least one of A, B, or C" may indicate including A, including B, including C, including A and B, including A and C, including B and C, and including A, B, and C.

[0444] It can be understood that various numbers in the embodiments of the present application are only used for distinction to facilitate description, and are not used to limit the scope of the embodiments of the present application. The sequence numbers of the above processes do not mean the execution sequence, and the execution sequence of the processes should be determined based on the function and internal logic of the processes.

Claims

1. 1. A method for antenna channel sounding, comprising: sending, by a first communication device, a first frame to a second communication device, the first frame comprising first indication information, the first indication information indicating to the second communication device to perform transmit antenna channel sounding; sending, by the first communication device, a first physical layer protocol data unit (PPDU) to the second communication device, the first PPDU being a Null Data Packet (NDP), the first PPDU being used by the second communication device to perform transmit antenna channel sounding, the first PPDU comprising a first identifier field, the first identifier field indicating an identifier of a first transmit antenna set.

2. After the step of sending a first PPDU by the first communication device to the second communication device, the method further comprises: receiving, by the first communication device, a second frame from the second communication device, the second frame comprising a first antenna selection feedback result, the first antenna selection feedback result comprising a third identifier field, the third identifier field indicating the identifier of the first transmit antenna set; The method of claim 1 further comprising:

3. Prior to the step of sending a first frame by the first communication device to the second communication device, the method further comprises: sending, by the first communication device, a fourth frame to the second communication device, the fourth frame comprising a fourth identifier field, the fourth identifier field indicating an identifier of at least one transmit antenna set supported by the first communication device, the identifier of the at least one transmit antenna set comprising the identifier of the first transmit antenna set; The method of claim 1 or 2, further comprising:

4. Prior to the step of sending a first frame by the first communication device to the second communication device, the method further comprises: sending, by the first communication device, a ninth frame to the second communication device, the ninth frame comprising seventh indication information, the seventh indication information indicating a total amount of transmit antenna sets supported by the first communication device; The method of any one of claims 1 to 3, further comprising:

5. 1. A method for antenna channel sounding, comprising: receiving, by a second communication device, a first frame from a first communication device, the first frame comprising first indication information, the first indication information indicating to the second communication device to perform transmit antenna channel sounding; receiving, by the second communication device, a first physical layer protocol data unit (PPDU) from the first communication device, the first PPDU being a Null Data Packet (NDP), the first PPDU being used by the second communication device to perform transmit antenna channel sounding, the first PPDU comprising a first identifier field, the first identifier field indicating an identifier of a first transmit antenna set.

6. After the step of receiving, by the second communication device, a first PPDU, the method further comprises: performing, by the second communication device, transmit antenna channel sounding based on the first PPDU to obtain a first antenna selection feedback result; sending, by the second communication device, a second frame, the second frame comprising the first antenna selection feedback result, the first antenna selection feedback result comprising a third identifier field, the third identifier field indicating the identifier of the first transmit antenna set; The method of claim 5 further comprising:

7. Prior to the step of receiving, by the second communication device, the first frame, the method further comprises: receiving, by the second communication device, a fourth frame from the first communication device, the fourth frame comprising a fourth identifier field, the fourth identifier field indicating an identifier of at least one transmit antenna set supported by the first communication device, the identifier of the at least one transmit antenna set comprising the identifier of the first transmit antenna set; The method of claim 5 or 6, further comprising:

8. Prior to the step of receiving, by the second communication device, the first frame, the method further comprises: receiving, by the second communication device, a ninth frame from the first communication device, the ninth frame comprising a seventh indication information, the seventh indication information indicating a total amount of transmit antenna sets supported by the first communication device; The method of any one of claims 5 to 7, further comprising:

9. The method of claim 1 , wherein the first identifier field is located in a preamble of the first PPDU.

10. the first frame further comprises an amount of NDP; and / or The method of claim 1 , wherein the first frame further comprises a second identifier field, the second identifier field indicating the identifier of the first set of transmit antennas.

11. the first indication information and / or the amount of NDP is of the first frame and is carried in at least one station information field comprising second indication information, the second indication information indicating that the station information field comprises antenna selection related information; and / or 11. The method of claim 10, wherein the second identifier field is of the first frame and comprises some or all bits in the at least one station information field comprising the second indication information.

12. The method of claim 11 , wherein the second indication information is carried in an association identifier field in the station information field.

13. The first set of transmit antennas is k of the first communication device. １ is one of the k transmit antenna sets, １ is a positive integer, The k １ The k transmit antenna sets are １ 13. The method of claim 1, wherein there is a one-to-one correspondence between the identifiers of the transmit antenna sets.

14. A communication device, 1. A transceiver unit configured to: send a first frame to a second communication device, the first frame comprising first indication information, the first indication information indicating to the second communication device to perform transmit antenna channel sounding. Equipped with the transceiver unit is further configured to send a first physical layer protocol data unit (PPDU) to the second communication device, the first PPDU being a Null Data Packet (NDP), the first PPDU being used by the second communication device to perform transmit antenna channel sounding, the first PPDU comprising a first identifier field, the first identifier field indicating an identifier of a first transmit antenna set. Communication equipment.

15. After the communication device sends the first PPDU to the second communication device, the method further comprises: receiving a second frame from the second communication device, the second frame comprising a first antenna selection feedback result, the first antenna selection feedback result comprising a third identifier field, the third identifier field indicating the identifier of the first transmit antenna set; The communication device of claim 14 further comprising:

16. Before the communication device sends the first frame to the second communication device, the method further comprises: sending a fourth frame to the second communication device, the fourth frame comprising a fourth identifier field, the fourth identifier field indicating an identifier of at least one transmit antenna set supported by the communication device, the identifier of the at least one transmit antenna set comprising the identifier of the first transmit antenna set; The communication device according to claim 14 or 15, further comprising:

17. Before the communication device sends the first frame to the second communication device, the method further comprises: sending a ninth frame to the second communication device, the ninth frame comprising seventh indication information, the seventh indication information indicating a total amount of transmit antenna sets supported by the communication device; 17. The communication device of claim 14, further comprising:

18. A communication device, 1. A transceiver unit configured to receive a first frame from a first communication device, the first frame comprising first indication information, the first indication information indicating to the communication device to perform transmit antenna channel sounding. Equipped with 11. The communications device, wherein the transceiver unit is further configured to receive a first physical layer protocol data unit (PPDU) from the first communications device, the first PPDU being a Null Data Packet (NDP), the first PPDU being used by the communications device to perform transmit antenna channel sounding, the first PPDU comprising a first identifier field, the first identifier field indicating an identifier of a first transmit antenna set.

19. After the communication device receives the first PPDU, the method includes: performing, by the communication device, transmit antenna channel sounding based on the first PPDU to obtain a first antenna selection feedback result; sending a second frame, the second frame comprising the first antenna selection feedback result, the first antenna selection feedback result comprising a third identifier field, the third identifier field indicating the identifier of the first transmit antenna set; The communication device of claim 18 further comprising:

20. Before the communication device receives the first frame, the method further comprises: receiving a fourth frame from the first communication device, the fourth frame comprising a fourth identifier field, the fourth identifier field indicating an identifier of at least one transmit antenna set supported by the first communication device, the identifier of the at least one transmit antenna set comprising the identifier of the first transmit antenna set; 20. The communication device according to claim 18 or 19, further comprising:

21. Before the communication device receives the first frame, the method further comprises: receiving a ninth frame from the first communication device, the ninth frame comprising seventh indication information, the seventh indication information indicating a total amount of transmit antenna sets supported by the first communication device; 21. The communication device of claim 18, further comprising:

22. 22. The communications device of claim 14, wherein the first identifier field is located in a preamble of the first PPDU.

23. the first frame further comprises an amount of NDP; and / or 23. The communications device of claim 14, wherein the first frame further comprises a second identifier field, the second identifier field indicating the identifier of the first set of transmit antennas.

24. the first indication information and / or the amount of NDP is of the first frame and is carried in at least one station information field comprising second indication information, the second indication information indicating that the station information field comprises antenna selection related information; and / or 24. The communications device of claim 23, wherein the second identifier field is of the first frame and comprises some or all bits in the at least one station information field comprising the second indication information.

25. 25. The communications device of claim 24, wherein the second indication information is carried in an association identifier field in the station information field.

26. The first set of transmit antennas is k of the first communication device. １ is one of the k transmit antenna sets, １ is a positive integer, The k １ The k transmit antenna sets are １ The communication device according to any one of claims 14 to 25, wherein the identifiers of the transmit antenna sets correspond one-to-one to the identifiers of the transmit antenna sets.

27. A communication device comprising a processor and a communication interface, said processor being configured to implement the method of any one of claims 1 to 13 through said communication interface.

28. 1. A communication device, the device comprising: a processing unit and a transceiver unit; A communications device, wherein the processing unit is configured to implement the method of any one of claims 1 to 13 by using the transceiver unit.

29. 14. A computer-readable storage medium storing computer-executable instructions that, when invoked by a computer, perform the method of any one of claims 1 to 13.

30. A chip system comprising a processing circuit and an interface circuit, the interface circuitry is configured to input and / or output signaling or data; A chip system, wherein the processing circuitry is configured to execute a computer-executable program such that a device in which the chip system is installed performs the method of any one of claims 1 to 13.

31. A computer program product comprising program instructions, which when executed on a computer enable the computer to carry out the method of any one of claims 1 to 13.

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